Related
If I attempt to launch my .net core app I get this message. I realize there are many posts out there claiming to fix this but I have tried every method they suggest and none are working.
If I go into the project properties under debug and change the port, then it will connect 1 time. Then if I attempt to connect again, it will give me the same error again. I can then switch the port back to the original and it will load one time, then it will fail any time beyond that, until I switch it again. Anyone have any ideas or fixes they used?
Thanks!
I had this problem. There is a hidden folder in directory of project that name is '.vs'. Close the Visual Studio and delete this folder. The problem will be solved.
I installed core 2.0 and updated VS 2017 to 15.4.3 today, had the same error.
I ended up changing the application to run on a different port, it worked for me.
I have tried to delete the vs folder but did not work.
Hope it helps.
I know there is already an accepted answer to this question, but none of the solutions worked for me and my solution may help someone. I am using VS2017 with an ASP.NET Core 2.0 Razor Pages project.
The error just started appearing for no obvious reason, and I tried the solutions posted here.
I ran the web app from the command line using the dotnet run command to see if that would bring up any meaningful errors, and there was a warning about the URL not being correctly bound. I looked in my projects Properties\launchSettings.json file and noticed that the applicationUrl properties were different.
Change the values for applicationURL so they are the same
Close the project and close VS
Delete the hidden .vs folder (as mentioned in the accepted answer)
Start up VS as Admin
Your app should work fine.
I was having this issue with Visual Studio 2019 with a clean branch from master. Restarting the PC solved the problem.
My colleague said he is having the problem about 2 times a month and other tries for solutions did not work.
It could also just be that there are iisexpress.exe processes hanging around in task manager which were running on the same port.
I've just found a couple and killing them solved this problem for me without needing to delete any .vs folder or changing ports or anything like that.
I gave up, and chose to run the project as self hosted, instead of 'IIS Express' in the play/run drop-down box.
In my case, the problem was caused by the port for HTTP and HTTPS being the same:
The ports must be different:
In a solution if you have multiple projects using ASP.NET Core in Visual Studio 2017 and you are trying to use the same port number you will get this error. You must have unique port assignment in your solution.
Go here in your project: Properties/launchSettings.json open this file and edit the port numbers here. Note: This is where you change the SSL port (two places).
Reason: VS/IIS Express maintains bindings to all the ASP.NET Core projects in your solution that use IIS Express as the server. For example if you use Kestrel or some other server you will not have this problem. VS creates a new port for each app when it is created in the solution to ensure you do not have port conflicts.
If you are trying to use Azure AD registered applications reply ports and trying to "reuse" your app registration, you might think to simply change the "app's" port so that you don't have to register it in Azure; this will not work. If you are just testing apps and want to reuse a registration then you must make sure that the app you are currently working on is the ONLY one on the port - manually. If you need to test two or more apps then you must register them in Azure AD individually as you would in production.
What worked for me and it is really simple:
Right-click project
Properties
Debug
App URL: change port to 5000
Done, hope helps someone.
Changin https -> http in my applicationUrl solved this issue in my case.
I have solved this issue by
adding exclusion to file devenv.exe in windows defender (anti virus, Win10)
how to know this is the issue;
when you load project defender will notify in notification unauthorized changes blocked. if this is the issue just add the exception as above mentioned.
For me above solutions did not work
But changing the IIS Express Bitness to x64 worked
I encountered this issue. Running VS in admin mode solved this issue for me.
Go to properties - select debug tab - change the App URL - e.g. to http://localhost:57520/
Something else can be running on your port that interferes.
This worked for me!
For me with VS2019, faced this same issue on start running our project.
So right clicking on IIS Express icon in notification pane near by DateTime pane in our laptop/Desktop. It will show up all running application, at last can find Exit. Click Exit there and run your project should work. That worked for me, without closing VS19 project.
After playing with netsh configuration trying to make the server accessible from outside, I added a new iplisten entry. The IISExpress showed the error Unable to connect to web server 'IIS Express' which was fixed after deleting the iplisten entry using:
netsh http delete iplisten <ip-address>
You can view the current list of iplisten entries using
netsh http show iplisten
They require running an elevated (administrator) command prompt.
It seems like IISExpress has no error message in this a case.
If you're hard-coding a specific IP address (not localhost), check that it hasn't changed.
Tried all. didn't work above.
changing host in applicationhost.config fixed.
change localhost to 127.0.0.1
<binding protocol="http" bindingInformation="*:50740:127.0.0.1" />
<binding protocol="https" bindingInformation="*:44381:127.0.0.1" />
It works after I reenter username and password for the application pool's identity account
Setting "Enable SSL" to false in project properties\Debug section worked for me.
It may not completely direct your case, but I just had to restart my (windows) system. The diagnosis of #Turneye may very well be the reason and his solution might accomplish the same result.
I added the localhost option on the applicationhost.config file and run visual studio as administrator and it worked for me.
<binding protocol="http" bindingInformation="*:6873:localhost" />
<binding protocol="https" bindingInformation="*:44320:localhost" />
<binding protocol="http" bindingInformation="*:6873:192.168.137.1" />
Some times running visual studio as administrator solves this issue.
For me worked by changing the applicationUrl in launchsettings.json file to different port number and that url to be same for all places inside this file.
In my case (VS 2019), all I have to do is Rebuild the code before I re-run the app after each code modification.
P.S. I am coding server-side Blazor.
If you've used netsh http add urlacl url=http://localhost:<port>/ user=everyone to add a specific url acl using the problem port then you'll need to delete it with netsh http delete urlacl url=http://localhost:<port>/ user=everyone.
Another solution is to run Visual Studio as an administrator which allows it to override the urlacl.
I was facing the issue multiple times in VS2019, then I realized when I make small edits and restart the IIS Express this problem is more pronounced. Some of the discussion above about ports make me think since I was closing the app by just closing the browser. So I believe the port was not released and it failed the start next time around.
I started closing the debug by clicking the "Stop Debugging" button in the VS2019. The issue didn't occur again for me.
I solved this by restart my laptop.
Rebuilding the solution fixed this problem for me.
For those of you using .Net Core 3.x and still struggling, like myself, I finally after days of searching found a hint to the problem https://weblog.west-wind.com/posts/2020/Jan/14/ASPNET-Core-IIS-InProcess-Hosting-Issues-in-NET-Core-31.
In .NET Core 3.x InProcess hosting for IIS is the default. OutOfProcess hosting externally runs Kestrel.exe and has IIS proxying requests into the external Kestrel HTTP host. InProcess hosting uses a custom IIS Module that bootstraps a custom .NET Core host right into the IIS host process which provides better performance and a smaller footprint.
Changing to "Out of Process" (Right Click Project > Properties > Debug > Web Server Settings > Hosting Model), closing visual studio, deleting the hidden .vs folder (as described in previous comments), and then running IIS Express in VS finally worked. If you ever change it back to "In Process" for testing and it doesn't work, you'll have to delete the .vs folder again after you change it back and close the project.
If you're like me and that got you over one hurdle and into another....
My next issue was i was getting this error This webpage is not available (with error code "ERR_CONNECTION_RESET") when running a request to ping the server in powershell (Invoke-WebRequest -Uri:https://localhost:{port}/{endpoint}). This thread mentioning the error lead me to a thread that mentioned a missing iss express development cert, which mentions solving it by running ./IisExpressAdminCmd.exe setupsslUrl -url:https://localhost:{port}/ -UseSelfSigned in the IIS Express program files directory in an admin powershell terminal.
I'm also gonna post my first issue here when trying to run IIS Express from Visual Studio, which was Cannot find C:\Program Files\IIS Express\iisepxress.exe. IIS Express was for some reason installed not only in my Program Files (x86), but in my second drive (D:\Program Files (x86)). After realizing that there is just no way to change where Visual Studio is looking for IIS Express (even though it's also installed on the D drive), I uninstalled IIS Express (which is probably how my dev cert got removed), in RegEdit changed my Program Files directory back to the "C\Program Files" folder (HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion > ProgramFilesDir key), and reinstalled IIS Express from Microsoft.
Finally, I can run my .Net Core API locally using IIS Express.
Good luck all!
I installed a retail version of Windows 8 Pro. I downloaded and installed Visual Studio Express 2012. I asked for and received a developers certificate. Then I tried to create a hello world app.
From there I get a "Unable to Activate Windows Store App" message box when I try to debug the app. Most commentary on the web says delete build directories. This didn't work for me
Does anyone have a solution for how to fix this and debug my app?
This happened to me once too, but the deleting build directories advice fixed it. Specifically, you just need to delete the bin\Debug and bld\Debug folders in your projects. Their contents will be regenerated by Visual Studio when you rebuild. I assume that this is only one project since it's a Hello World app; otherwise I would ask if you deleted build directories from all projects in your solution.
You can also try running "Clean Solution" from the BUILD menu in Visual Studio.
I'm sorry...it's horrible if this is happening on a clean install as you describe.
I ran into the same issue, and tried rebuilding, cleaning, deleting temp files, rebooting the computer, etc... and nothing helped.
Then finally I made a release build then went back to debug. And now it works.
I have no idea what happened, nor if that really helped, but it's worth a try.
For me a RESTART of pc solved this error message.
For me the problem was that I created the app on a TrueCrypt mounted virtual drive and when I moved the project files to a normal drive then everything worked just fine. Weird.
I was getting the exact same error. In my case the culprit was a NuGet package. It had added an app.config file to the project and it was confusing VS. I removed the app.config file and it solved my issue.
I got the solution at Iris Classon's site.
This can be solved by Uninstalling the app from the start screen then again building the app from Visual Studio.
I had a similar problem, and the cause was creating the project on a USB thumb drive. Creating a project on a normal hard drive volume works.
this can happen when the application signing key (.pfx file) is missing.
Try the following:
Open the Package.appxmanifest file in Visual Studio
Go to the register "Packaging"
Select [Choose Certificate…]
Select the test certificate using [Configure Certificate…] [From File…], or create a new one using [Configure Certificate…] [Test Certificate…]
When using a test certificate, ensure that it is in the .gitignore file. There should be an entry like !**\*_TemporaryKey.pfx to include the key in Git.
Note: The certificate for release build should only be available to the build server and not included in Git.
Rebuild the project
This has happened to me in the past and I have always found that deleting the build directories resolves it.
However this time this is not working for me.
I have tried
- Rebooting
- Deleting build directories
- Running Build | Clean Solution in VS
- Renewing Developer Account
The only thing that will work for me is changing my Package name under the Package.appxmanifest
However I am not overly happy with this as a solution. I will keep investigating.
The issue might be caused because NuGet will try to add an app.config with binding redirects to Windows Store apps if it thinks it is needed. However, Windows Store apps don’t need app.config, and will actually fail to start with a very confusing error message if it is present.
And the solution in this case would be to Remove the App.config
This error generally comes when you try to deploy in debug mode.
I would suggest, deploy the app first in release mode and then try in debug mode.
This worked for me.
Making a new certificate works for me. For this, go to Package.manifest->Packaging, and follow the Choose certificate.... Click on Configure certificate and select Create test certificate. Give it a name and press OK.
Increasing the revision number of the package worked for me
Tried so many of the above fixes. Nothing worked (deleting bin, obj dirs, editing the manifest, editing the registry, changing package name, etc, etc.) My Avast antivirus software was running and so I uninstalled it completely. That was it. App now runs fine.
This sort of problems are common with Windows 8 Visual Studio. Such errors encounters when your developer license of Visual Studio has expired so you may want to renew or get a new developer license here's how you get that. How to get a developer license in Windows 8
And similar problem may also encounter with E_Fail issues here's how to solve Unable to activate Windows Store app E_Fail Issue
For me, the fix was a combination of two of these answers -
Renew the developer license (How to get a developer license in Windows 8)
And deleting the build directories (though I deleted more then the screenshot depicted) Delete the Build directories
NuGet will try to add an app.config with binding redirects to Windows Store apps if it thinks it is needed. However, Windows Store apps don’t need app.config, and will actually fail to start with a very confusing error message if it is present.
Solution:
Remove the App.config
and build again
For those who get a similar error but who are searching for a solution while debugging an IOT background app on a local machine specifically - you can find it here.
Using the search term "unable to activate windows store app the activation request failed with error" brought me here.
Because of Two things i resolved this issue.
Basically, we just need to delete the bin\Debug and bld\Debug folders in our projects. Those contents will be regenerated by Visual Studio when you rebuild project.
Just Restart the Visual Studio. And Clean Build and Rebuild the solution and RUN it.
Hope this helps.,
Playing with this issue for 3 days, tried every suggestions, nothing works. Until now!!!
The solution was this for me:
renew developer licence
build and deploy solution in Release mode (after this step it still not worked, but VS installed some packages in rpi)
start VS remote debugger with default account (http://:8080/#Debug%20settings)
configure remote device with Universal authentication mode (VS2017 -> Project settings -> debug -> target device: remote machine, authentication mode: Universal (unencrypted protocol))
...and now I can sleep.
Hope it helps somebody.
This gift was courtesy of Microsoft's automatic updates for VS2015 which was one of the 2 culprits:
KB3022398
KB3165756
It also broke SourceTree and other apps that draw the GUI - making an outline of the app but not drawing the contents.
For me changing the Package Name in Package.appxmanifest fixed the problem
In my case, the C# UWP app had a native library which failed in the application startup code, and called exit(1). The symptoms were identical to those in the question, though. Visual Studio would throw a message:
Unable to activate Windows Store app '88888888-6666-5555-4444-111111111111_abcdefgh!App'. The Acme.exe process started, but the activation request failed with error 'Operation not supported. Unknown error: 0x80040905'.
In addition, there was a message in the UWP app Windows log under Microsoft\Windows\Apps\Microsoft-Windows-TWinUI/Operational: event ID 5961, message:
Activation for 88888888-6666-5555-4444-111111111111_abcdefgh!App failed. Error code: Unknown HResult Error code: 0x80040905. Activation phase: COM App activation
Internally, the C# part would try to construct a native class instance from the App constructor, the native class constructor would encounter an unrecoverable error and bail. From the UWP subsystem standpoint, and from the debugger standpoint, though, this looked as something distinct from the mere programmatic exit. I'll leave this answer here, 'cause I've spent some time chasing various UWP failure scenarios instead of running under a native debugger.
I've replaced the exit() call with throw ref new Exception(E_INVALIDARG). At least this way the error manifests in the managed debugger, and the message is descriptive.
I've been having this problem a lot with a UWP Windows 10 app on Visual Studio 2019...for me the reliable workaround is to bump the Build number in the Package.appxmanifest file (Packaging tab). It's a huge pain...really hope Microsoft will sort this out soon
Any existing error in the code can also cause this issue. Make sure your previous version of the code is working fine. Compare the difference and make sure all looks good.
I was getting this error and nothing else worked so I had to dissect my program. Turns out I referenced a StaticResource in my App.xaml that didn't exist.
Seems like a silly error but you'd also think Visual Studio would pick up on something like that and throw a different error so if nothing else works, double check your application resources.
As suggested by #Iman in a comment, in the UWP project settings, enable "Compile with .NET Native tool chain".
(After trying just about every answer in this question)
I have a simple Silverlight program that displays a bunch of images. I modified it do display more images, but it when I hit "run without debugging" is keeps running the old build with fewer images. When I copy the code into a new project and run it, it works fine for the first time, but then each subsequent change is not displayed. What could be the problem? I'm using Visual Web Developer 2008 Express.
Always check "Configuration Manager" option on "Build" menu in Microsoft Visual Web Developer. The checkBox "build" has to be checked, otherwise it won't build.
Happened to me, I hope this helps others.
I just had this happen to me in VS 2013 for Web. Had to change the Project URL in:
"Project properties"
"Web" tab
"Servers"
To a different localhost number and recreate Virtual directory.
Before my Project URL was:
http://localhost:55487/
I changed it to:
http://localhost:55488/
Then clicked "Create Virtual Directory".
Would like to know why this happened in the first place.
I found that I had to close all open instances of Visual Studio before I got it working again
This happens because your cache memory is full. just go to you bin and obj folder and delete all the temporary files. Now it will run properly.
Maybe it's a caching issue (webbrowser / proxy).
To fool the browser try to embed the xap file with an additional parameter that changes every time you open the plugin:
<param name="source" value="ClientBin/BubuApp.xap?<%=Guid.NewGuid().ToString() %>"/>
If this don't help, try to clean the project (delete obj / bin folders & xap file).
I was also suffering from this issue and none of the suggestions worked. I was building a Office.js add-in and debugging was with IIS Express.
What fixed the issue for me was deleting files in
C:\Users\<user>\AppData\Local\Temp\Temporary ASP.NET
Actually, I went ahead and and deleted the entire C:\Users\<user>\AppData\Local\Temp folder out of spite :)
I also had this issue and while some of the fixes above helped temporarily, the one that worked for me was to remove the history and caching in Internet Options.
Go into Internet Option (also available in VS via Tools > options > Environment > Web Browser > Internet Explorer Options).
On the General tab click Settings in the Browsing History section.
On the Temporary Internet Files page select Every time I start
Internet Explorer
On the History tab set the Days to keep history to 0
On the Caches and Database tab make sure Allow website caches and
databases is NOT ticked.
I'm not sure if all of the above are required, but I've made a number of changes to files and so far they have been reflected straight away in the dynamic versions without any noticeable performance problems.
I've also since realised if I set 'Every time I visit the webpage' instead of 'Every time I start Internet Explorer' I don't have to stop and restart the project to see the changes. Which is how it should be!
I used to suffer this. All of this used to be (for me) a folder's contents issue.
Maybe you can check this:
Delete %windir%\microsoft.net\framework\v4.0xxx\Temporary
IIS Express: even if you change the output file for compiled results, you will see in applicationhost.config that many times IISExpress is really "looking" to the default bin folder of your project.
It is even possible that you have different configurations for Debug or Release, so maybe IIS is looking BIN with Release code, and you are now compiling in Debug to another folder, do you understand me?
Happened to me too. Well i dont know the exact reason for this behavior. But when i close the visual C express 10 and then open again and build it builds the new saved file. I guess it still hangs on to the old file when there is an error in some debug mode or something.
Stop all incntance of VS.
Delete all /bin, not just /bin/Debug. All /bin
Remove user option .suo file in solution dir. It will create on self.
Remove all restore windows point
Stop IIS.
6 Start IIS after 1 minutes.
Rebuild solution, Buid projects
It happing on me too. Very nasty. You may restart your computer.
Check for global asembly dll.
Just delete folder 'Release' in project with old code build.
I had the same problem and none of the answers were working for me. It turns out that building the ASP.Net project did not build the Silverlight project, so running without debugging didn't update the Silverlight.
Fix: Right click the Asp.Net project. Build Dependencies > Project Dependencies. Check the Silverlight project. Now building should work.
If this is a web application, change the Project URL with a new port number.
Example :
Change from http://localhost:3688/
To http://localhost:36881/
To do this:
Navigate to Project properties -> Web
Change the URL
Hit "Create Virtual Directory"
Finally, Build and RUN
I had this issue in a web site.
The site referenced 1 of the projects in the solution, and changes to it would not reflect in the debug.
Issue was a third project was referencing an outdated dll of the same same referenced project.
I removed the project and all references in other projects and readded and re-referenced everything and it worked fine.
Check you haven't got two versions of whichever file you're updating (one for one group of users, one for a different group of users).
In my case(VS 2015) it was because of the missing dll in the .exe directory... I made a "clean solution", then additionally deleted all bin and obj folders' contents. Reason to do so was VS keeping to load old dll build. Solution was to select folder of the running debug config, i.e. everytime I rebuild project destination location with dll and a reference to it stays with warning mark for some time until intellitrace does its job. After doing the setup mentioned above, I still have to do a manual rebuild on a project that generates a dll into specified dir. Pressing F5 does nothing, I don't have time to find out why... Main thing is its working for me
I had this recently too and I didn't see the answer here. I was changing an MMI to get rid of redundant buttons, and they didn't go away.
Really old legacy code. To make it keep user settings - like language - someone had made it keep the Settings. I was not allowed to change this, they want it like that.
To get rid of the old settings and allow new ones:
open regedit
navigate to HKEY_CURRENT_USER - Software - MyProject - SubProject
here you see Recent File List and Settings.
Delete Settings completely - don't worry, it will make a new one.
Please check is there any old .tlb file present in someother folder. In my case i was using the .tlb file generated using .NET dll and then created the .tlb file using RegAsm. I tried to use the .tlb file in vb6 code, it still refers old code only. After a long search i found same .tlb file older version found in Visual Studio\VB98 folder. I removed it then it worked fine. This may not be relevent for this issue but could give you another way of thinking
There is a scroll bar at the top which has 3 options:
debug
release
configuration manager
Make sure release is selected.
I had to clear browsing data and it worked in my case
I'm unable to debug a WinForms C# application using the released version of Visual Studio 2010 Prof.
I get the following error message after the second debugging run.
Error 9 Unable to copy file "obj\x86\Debug\Arrowgrass Reports.exe" to "bin\Debug\Arrowgrass Reports.exe". The process cannot access the file 'bin\Debug\Arrowgrass Reports.exe' because it is being used by another process.
I've tried a pre-build script to attempt to delete this file, but it's locked by Visual Studio.
There are a few references to this on the net so it is a know problem. Does anyone have a hotfix or effective work-around?
I have found this issue very easy to reproduce, and the fix for me is a variation on Richard Fors' answer. If I have a UserControl open in the designer, run the debugger, and then edit the UserControl, the subsequent rebuild will fail. If I close the UserControl before running the debugger I never get this error, so I just make sure to close the designer window before hitting F5.
As of October 2012, I still have that issue so the VS 2010 SP1 didn't solve the problem. What I did, and worked consistently, was disabling the hosting process in the projects.
To disable the hosting process:
. Open a project in Visual Studio.
. On the Project menu, click Properties.
. Click the Debug tab.
. Clear the Enable the Visual Studio hosting process check box.
Source:
http://msdn.microsoft.com/en-us/library/ms185330(v=vs.100).aspx
You can try to kill the vshost.exe process:
taskkill /F /IM "Arrowgrass Reports.vshosts.exe"
You might also be lucky and simply be able to move the file in question. Moving the file can be done by adding the following lines of code to the pre-build event of your project:
if exist "$(TargetPath).locked" del "$(TargetPath).locked"
if exist "$(TargetPath)" if not exist "$(TargetPath).locked" move "$(TargetPath)" "$(TargetPath).locked"
Disabling windows search did not fix for me. However disabling Antivirus did (our Antivirus is Symantec Endpoint Protection 11)
As such, I was able to fix this for myself by changing the Debug settings in the project to point the working folder to a path on the C: drive, and then excepting that path from the antivirus auto-protect scan settings.
I hope this helps someone.
I posted this answer in a similar question but figured I'd also say it here:
Alright... this might sound pretty crazy.
I've had this problem in VS2010 for the last couple of years. The workaround mentioned here works for me, but a lot of times I forgot to close all my forms/usercontrols first.
I've discovered that merely going to view the open files via:
Computer Management (compmgmt.msc)->Shared Folders->Open Files
will "Free up" whichever file is being locked. Very strange, but it works for me!
In my case, I did Project Properties-->Security Tab-->Uncheck Click-Once security settings (If it is checked). It worked for me. In my project, it was showing this error for a C++ dll being used in my C# project.
The condition described can also be caused by the offending DLL or EXE referencing itself; in which case the Process Explorer test described previously never returns a match (e.g. it's not running). This unexpected situation seems to be caused during some sequence of operations in VS2010 (and likely all previous versions) which insidiously adds the reference behind the scenes. The specific cause of this hasn't been tracked down (or resolved that I know of). To check for, and resolve this error simply make sure the offending DLL or EXE is not listed as a reference to itself.
Got the error ("The process cannot access the file … because it is being used by another process") when I modified the (Visual Studio 2010 C# Express with SP1) solution from two large (10 source files, ~500 lines per file) projects with one referencing the other, to lots (6) of smaller projects with lots of projects referencing other projects.
The references were to the dll- and exe files (the Debug versions of them), NOT to the projects even though the projects were in the same solution.
I then learned that references should be to projects, not files, for F12 to work properly. So I modified the references. That made F12 work (jump to the source file instead of some auto-generated interface description), and at the same time the "cannot access file" error during build disappeared.
I only got the "cannot access file" error when doing Release builds. The references were to the Debug versions of exe/dll's. I suspect that this mixing is what triggers the bug in VS.
I encountered this issue when developing windows services. I found out that it happens when the service is running. Thus, you only need to stop the service (from the services.msc console) and you're good to go !
Hope this helps.
Tidjani.
Check Task Manager for the specified process and End the process explicitly. This solution worked for me.
I cant' write to a comment since not at 50 points but for me I excluded my project folder in ESET Enpoint Security ver 5. Seems like it blocked/hogged some files. My Error did not state which exe or file was in use so it took a long time to finally get to what JoeC said about Antivirus and tried it. Seems to be working now (Visual Studio 2010 SP1)
Closing recently changed User Controls solved the problem in my scenario. Hope this will help somebody out there.
Looks like this issue has (finally!) been fixed in the VS2010 SP1
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=75568aa6-8107-475d-948a-ef22627e57a5&displaylang=en
Please try uninstalling Windows Live SYNC. Does it still happen?
I think I just found the culprit and the solution.
Go to services and stop & disable the "windows search" service.
That solved the problem for me now.
For me the solution was to change the startup project to a dll (problem only occurs in debug mode when having an application as the startup project). If your solution contains several projects (and it will, and it will contain a .dll, else you would not get the problem), switch to that .dll, no .vshost.exe, no problem.
Also, killing .vshost.exe did not work for me, since immediately after starting again, it had locked the .dll.
Also, make sure to have your references clean, especially in more complex projects, and also prefer project references to assembly references, and so on. I suppose bad references (circular and similar) are bound to cause problems, at least so I have read.
A short article by me on this problem (and my solution)
How to "clean up" your references in a solution
Adding the following to the Pre-build event of the shared dll worked for me:
if exist "$(TargetPath).locked*" del "$(TargetPath).locked*"
set exitprebuildfor$(ProjectName)=
for /l %%a in (1,1,10) do (
if defined exitprebuildfor$(ProjectName) goto :ok
if not exist "$(TargetPath).locked%%a" if exist "$(TargetPath)" move "$(TargetPath)" "$(TargetPath).locked%%a" & set exitprebuildfor$(ProjectName)=1)
:ok
set exitprebuildfor$(ProjectName)=
It's based on the solution given here but instead of just renaming the dll to .locked it keeps trying to rename it to .locked1, locked2. Using 10 I usually run into the problem once a day, but ant value can be used.
Simply make a copy of the whole project and run project from the new copy.... it will work fine.
But you will have to end process of the debug somehow in-order to delete the older project.
Stop IIS service and try building it again or if you can afford to restart your pc, give it a try. Worked for me both ways.
Cheers
My problem was that Outlook 2010 (outlook.exe) was using the same port as my ASP.NET MVC project with IIS express.
Solution: close outlook.exe, run your solution and open outlook again (so that it uses another port).
Hopefully this helps somebody, because I received the same error message as described in this topic.
Try deleting .exe file in debug or release folder (whatever you working on)
Windows will prompt that the process X has opened this and you can't delete it
after that go to task manager and in details tab end task X process
Delete obj file.And stop your service and Restart again.Then you may solve the problem
The best solution for me was to move my project files out of My Documents - which is on a server managed by the IT department - and locate them locally on my C drive. Also working: unchecking the "Enable the Visual Studio hosting process" checkbox, as stated by other people.
If you are working on a C# project which is using reference of C DLL, then you can eliminate the error by checking the Allow unsafe code check box. I know I have not used pointers in my C# project but I was using some bitwise operator in C#. May be these C-like features morphed it as 'Unsafe' code.
What worked for me was removing "read only" status on the bin folder. Once I did that, it has worked ever since.
I've had this error when the project is on a remote share (like, if your $env:homepath is helpfully redirected by your IT department to a network share). Make sure your project is resident on a local drive.
My problem started after creating a custom control and drag and drop it to the toolbox palette for use it in design forms. First appeared a warning saying that there was a redundance between the custom control source file (.cs) and the projects executable (.exe). On executing/debugging appeared the error: unable to access the (.exe) because it's being used (and it was true).
A literally removed the whole source code regarding the custom control and last problem never stopped, until I checked out the references and it was referencing itself in order to be "able to" get the former custom control. I removed the reference and done!!
So: just check the references and remove the self-reference to the project.
Delete your Bin folder and run the application.
This worked for me. :)
Simply turn off Visual Studio hosting in debug, run the project and again re on it and run project.
Open a project in Visual Studio.
. On the Project menu, click Properties.
. Click the Debug tab.
. Clear the Enable the Visual Studio hosting process check box
For Windows Project
The Visual Studio hosting process can hold the executable file pointer. To stop the host instance, open the Project properties and then go to Debug tab. Now uncheck the Enable the Visual Studio hosting Process option and then check the checkbox again to debug.
For web project
The IIS can hold the file pointer. Restarting the IIS can solve the issue.
I just added xUnit to our test project (for the Asserts, we're still using MSTest as the framework) and immediately the test runs refused to execute any of the tests. This is the error message:
Failed to queue test run '{ .... }'
Test run deployment issue: The
location of the file or directory
'...xUnit.dll' is not trusted.
It took me a few tries to find the answer in Google, so I'm putting it here in case anyone else runs into the same problem. A detailed description can be found at this blog posting.
Basically, the fix invovles right-clicking on the dll file (xunit.dll for example) in Windows Explorer, going to Properties, and clicking "Unblock" at the bottom of the tab next to the 'Security' text. It seems that Vista / Windows 2008 will automatically mark assemblies that come from other machines or the internet as unsafe.
As a couple commenters have mentioned, you may also need to restart Visual Studio for this to take effect.
In my team we had the same problem.
Your solution didn't work, but this post by Charles Sterling did help.
We used the following line:
caspol -machine -addgroup 1 -url file://\\server/share/* FullTrust -name DevShare
After having this issue and burning hours trying to get "Unblock" to stick longer than a few minutes and/or figuring out caspol to no avail, I finally found a little tidbit via Google that the assemblies will be blocked again the next time you build or rebuild the project, since they're re-copied from their original source location. (I guess I never noticed that this happened before with references assemblies, but anyway...)
My fix for this was the following:
Copy all the needed DLLs to another
spot for safe-keeping
Remove the
references in Visual Studio
Physically delete the DLLs in the
bin folder
Unblock the DLLs
individually in the spot where they
were copied off
Add the references
back in Visual Studio from the
holding spot
Every subsequent build or rebuild worked fine afterward.
Running on an XP machine (even with .NET 3.5 SP1 installed) I was not able to get any of the other solutions listed here to work.
However working from the same post by Charles Sterling that Davy Landman references, I finally succeeded with this variation:
Run the .NET 2.0 Configuration tool (Settings... Control Panel... Administrative Tools... .NET Framework 2.0 Configuration)
Click down to "My Computer ... Runtime Security Policy ... Machine ... Code Groups ... All_Code"
Create a new code group with membership condition of "Zone"="Local Intranet" and assign the permission set "FullTrust"
Restart Visual Studio
After these steps I am able to run tests, including after restarts and rebuilds.
EDIT: as described in this answer, you may need to install the .NET SDK (which is different from the .NET framework) in order to have the .NET 2.0 Configuration tool on your system.
I had the same problem with moq. But would not 'unblock'. Every time I unblocked it, it was still blocked!?!?
I had to unblock the original zip file I downloaded. Then copy the DLL from the zip file again. It work after that.
It may seem really obvious now, but when I was clicking unblock the file was set as read-only.
Only after un-checking that attribute, applying, then selecting unblock did I actually get this working.
Give that a go.
:)
PS: I also deleted all the old dll's in my bin folder, just to make sure Visual Studio wasn't picking up the old one.
I had the same problem with downloaded DLLs blocked by Vista.
You need Administrator rights to get the "Unblock" button on the file's Properties.
I simply replaced the DLLs with the latest version from source control (TFS) where I had committed them before.
Go to file
Right click and select Properties
On the first Register click on Allow
I also tried opening the file in notepad++ and renaming it.
Slightly different approach, but it worked for me. The local file system then think it comes from the same machine.
It's not just the moq.dll that needs to be unblocked. The latest zip file includes an moq.xml and moq.pdb file - referencing the dll copies these other two files to the bin folders as well. If all three have not been unblocked the tests won't run, I found.