Cannot edit checked out file (TFS) in Visual Studio 2013 - visual-studio-2013

Since I changed my windows password I can no longer type into a checked out file in Visual Studio 2013! Where before I just needed to start typing and it would check out the file in the background, now it won't even allow me to type into the file after I manually check the file out, from the solution explorer! It's as if VS 2013 is ignoring the keyboard on the project under source control. It's fine for other projects even project's under source control!
I think I remember seeing this before with older versions of Visual Studio and resolved it with a "Go online" option but I can't see that option in VS 2013, or the project is not "off line" so the option is not available.
This is obviously related to the TFS setting on the project but I simply cannot get past it. I am blocked and would appreciate any suggestions.

I suspended Resharper and restarted Visual Studio 2013. Once I reopened it the problem was gone. Resuming Resharper caused the problem to emerge again.
The solution is quite large so maybe that is it. Before putting Resharper into suspend mode I tried switching off code analysis thinking the workload is just too great, but that didn't help. The suspend did though. I hope this helps anyone else with the same issue.
All I have to do now is to figure out how to get Resharper back in the game without the problem coming back. We rely on Resharper as it is an wonderful tool. Since the solution has many projects in it, I am going to try create a smaller solution with my web project and just reference the other projects as assemblies. Maybe that will help
Update:
Clearing the resharper cache as suggested by Alexander resolved the original issue.

I'd like to add Alexander's comment as answer, since it helped me exactly to solve the issue:
Clean R# (ReSharper) caches by deleting all folders (and files) from the path
C:\Users\{User Name}\AppData\Local\JetBrains\ReSharper\v8.2\SolutionCaches\
and then reopen the solution.
Note: (Thanks to Antak for providing this info!)
You can paste
%userprofile%\AppData\Local\JetBrains\ReSharper\v8.2\SolutionCaches
into file explorer's path textbox (open it via Win+E, or use Win+R and paste the path into the command window), this will resolve the physical path into your user's directory automatically.

This happened to me. All my JavaScript files went "dead." By "dead" i mean that all the normal VS intellisense coloring/functionality was gone; js files were un-editable, although Resharper was still working sort of; all other non-js files seems to be normal. In addition to Resharper, I had also previously installed Web Essentials and was using both tools.
First, I cleared the R# caches as mentioned above by Alexander. After restarting VS, this DID NOT work. JS files still dead.
Then i disabled Web Essentials. Then I restarted. THIS WORKED.
I then re-enabled Web Essentials, restarted again, and all seems to be OK. Am crossing my fingers....

I too had this problem with the latest version of ReSharper (9.0.0.0), but clearing the cache as stated above did not work. I actually had to go into my ReSharper options (ReSharper -> Options -> General) and click the "Clear Caches" button. Once I did this and restarted VS everything is working again.

Try: /safemode
I had a similar problem where I could not edit most of my files, but I could edit *.ps1 files.
I don't have TFS, I do have resharper and other plugins.
What worked for me was:
Start visual studio in safe mode: C:\..\IDE>devenv /safemode
Close VS.
Start VS normally.
That probably has the same effect as suspending and resuming resharper, but I'm not sure which plugin could be causing the problem. If you are having trouble this is something you could try.

I hit the refresh(restart) and it solved a similiar problems so maybe you better try that before an IDE restar. ctrl shift F5

Related

Visual Studio freezing (crashing) while loading solution

I've met with a strange problem. I had 7 projects in the solution. I had to add another MVC project. Now when the document (from the new project) is opened (for example HomeController.cs) and when this project is initializing at the start, it freezes the whole IDE like this:
(Some projects do not load)
After that, I have to kill the process. When I open VS again and fast click on another project (which is initializing) the freezing issue is gone. I have no idea what can cause a problem like this. I've tried with and without ReSharper but I get the same result. Also, I restored default settings of VS. Also repaired whole VS.
Maybe someone had the same problem and could give some helpful advice?
Usually removing of the hidden .vs folder in solution directory fixes the problem.
Possible solutions:
Delete .vs folder as mentioned above
Clear temp files from %USERPROFILE%\AppData\Local\Temp
Readjust source control in Tools -> Options -> Source control -> Plugins, set to None, Save, close VS. Then reopen it and reset the plugin.
There is no particular order, but one of them might help.
I experienced the same issue with VS 2019 and fixed it by deleting the user.json file from %USERPROFILE%\AppData\Roaming\Visual Studio Setup
EDIT
The issue reappeared after a few days, so I located the user settings for Visual Studio 2019 (%USERPROFILE%\AppData\Roaming\Microsoft\VisualStudio\16.0_f124b472) and deleting the following files seemed to have reset VS to a normal state:
Current.vsk
User.vsk
ObjBrowEx.dat
Please close all your solutions before deleting the files
I used to have this problem, it was solved just by double clicking any of the stuck projects. This nudges the loading process somehow and causes unloaded projects to complete its loading.
Delete the .suo file in the solution folder.
I am pretty sure I found this answer somewhere on Stackoverflow before, but now I can't find it anymore. Credits to whoever came up with this.
None of above answers worked for me and found this solution.
By opening solution in safe mode devenv.exe /SafeMode will show you details about file causing issue and then
Search for all the files in the project directory with extension *.user
and remove them all
last reloaded the projects
For Visual Studio 2019, I cleared my %USERPROFILE%\AppData\Local\Temp folder.
It worked.
When you get over the past install multiply versions and the previous version was not fully uninstalled. This cause this issue in my case.
Control Panel > Programs > Programs and Features
Search for all Visual Studio related programs and Uninstall those.

Visual Studio Xamarin Intellisense Not Working

While using Visual Studio 2015 with the latest updates, Intellisense and CodeLens do not work properly. Syntax highlighting, code completion, and property/method references (not sure the exact name for this) are shown very inconsistently, or not at all. These work for some things, and don't for most others. Errors do not show up at all without an explicit build, and even then, they show up one at a time, which is very time-consuming.
I should note that this is not happening in XAML, just my .cs files. I was not able to reproduce these issues in either a WPF project or a Windows Forms project; I'm only seeing this in my Xamarin.Forms solution.
I've tried restarting VS, closing the solution and restarting VS, restarting my machine, resetting the "Statement Completion" settings in VS options, deleting the solution's .suo file, resetting settings via the Import and Export Settings Wizard, but nothing has changed. I would appreciate any suggestions.
Update: Uninstalling all Xamarin-related VS extensions and NuGet packages, then reinstalling seems to have fixed things, at least for now.
Further update: I ended up seeing this problem again not long after my first update. It turns out the path for one of my projects had too many characters (???), so I moved the whole solution folder to the root of my C drive. I haven't had any problems since.
For those, having xaml intellisense problem and you are using Resharper;
Disable ReSharper!
Visual Studio > Tools | Options | ReSharper | General : Suspend
Update:
When I install the latest ReSharper version (2017.2), the problem is solved.

CodeLens not showing references

CodeLens stopped working for some reason in project solution that I'm dealing nowadays. It is not showing references instead "- references". However, when I open up Visual Studio with another project It works like charm.I can confirm that CodeLens is enabled. Do you have any idea to make it work?
My Solution:
Toggle the CodeLens feature off and then on again.
Note: Many have found the feature to be turned off after an update so you just need to turn it back on. Thanks to #razblack for calling this out. Don't forget to give his comment an upvote if this was your issue!
Go into Tools -> Options... -> Text Editor -> All Languages -> CodeLens.
Uncheck "Enable CodeLens" option and click OK.
Go back into Tools -> Options... -> Text Editor -> All Languages -> CodeLens.
Check the "Enable CodeLens" option and click OK.
Note: I've fixed the issue once before by closing the problem .cs file and then reopening it. Closing any referenced files may also be required.
My Problem(s):
Similar to the original poster, CodeLens stopped refreshing references after I made a bunch of refactors. I was seeing stale references to code that didn't exist and I was also seeing the "- references" issue as described in the original post.
My Environment & Specific Scenario:
Visual Studio 2015 with Service Pack 2 and Resharper Ultimate 10.0.1
I was doing a major overhaul with a ton of refactoring and my project wasn't compilable for an hour or so. Once I could compile the project again, the references weren't working.
Same problem here.
CodeLens works normally with small solutions, but not working with large ones.
And this behavior is accompanied with crash of Alm.Shared.Remoting.RemoteContainer.dll process.
Tried in VS 2013 Update 4 and VS 2013 Update 5 RC.
Solution:
Close all programs and clean %LocalAppData%\Temp folder (or maybe just ALM folder inside it).
A simple solution, which works!
I did try enabling CodeLens in Visual Studio (2015) -->
Quick Launch (Ctrl+Q)
Options (CodeLens)
But, it was enabled :( Then, it did work with: (Closing the programs),
Win+R --> %temp% EnterDelete all
For me, CodeLens was disabled, so make sure it is still enabled.
I know it is an easy answer, but it might help some developers.
Go to Tools -> Options -> Text Editor -> All Languages -> CodeLens then click the "Enable CodeLens" option if it is not checked and then save it.
It looks like VS disabled it for some reason, maybe after an update or slow startup.
Try to remove .suo file which is storing some enviroment/solution settings. This helped me.
Just had this problem with VS 2019.
I tried disabling / enabling codelens and it didn't work.
I deleted the .suo after that and it didn't work.
I tried disabling / enabling codelens again (after deleting the .suo) and now it works again.
UPDATE (about 2 weeks later):
It started happening again and this time I disabled IntelliCode in Extensions and all of a sudden Codelens started working again.
UPDATE AGAIN (25 Nov 2019):
I reported this to Microsoft and had a dialog with them. You do not have to turn off all of Intellicode at this time, only disable Intellicode Refactorings in Tools -> Options -> Intellicode. The actual fix is slated for VS 2019 16.4 I believe.
You may have circular references in your solution that prevents CodeLens from working. Some details were provided in the comments for this issue on the Visual Studio Connect site:
Somehow, two of my projects in my solution ended up referencing each
other causing a circular reference. I think it was a by-product of
Resharper's shortcut to reference an undefined class. Once I was
cleaned up all of the references, I'm now getting valid values in my
reference counts.
How did you go about "cleaning" up references?
In my case, my solution has multiple project files. In the references
folder of Project A, there was a reference to Project B. In the
references folder of Project B, there was a reference to Project A.
This was causing the circular reference. If you try to do this
"manually", VS will prompt you with a warning regarding the circular
reference.
To clean this up, I removed the reference to Project B from my Project
A. I had do some minor class definitions in my Project B so everything
would still compile in the end.
I found out that if you block the Visual Studio with the Firewall, the Code Lens did not work.
So unblock it from the firewall to make it work.
Or edit Firewall settings for file:
C:\Windows\Microsoft.NET\assembly\GAC_32\
Microsoft.Alm.Shared.Remoting.RemoteContainer\
v4.0_12.0.0.0__b03f5f7f11d50a3a\
Microsoft.Alm.Shared.Remoting.RemoteContainer.dll
I had this problem with VS2015 that already had "update 1" installed.
The thing was that I originally installed VS2015 with the "custom" setup, not the "default" option, and I accidentally left out the "Git for Windows (3rd party)" option under "Common Tools".
This can be fixed by these steps:
Run the VS2015 setup again (from control panel - uninstall program)
Right click VS2015, select "Change"
On popup screen, select "Modify"
On setup screen, select "Git for Windows (3rd party)"
Move on with the setup, install selected features
In Visual Studio Professional or Enterprise you can enable CodeLens by doing this:
Tools → Options → Text Editor → All Languages → CodeLens->Enable
This is not available in some Community Edition versions
Try deleting .suo file inside of the hidden .vs folder in your project. This worked for me in VS 2017.
My Problem
Always directly after enabling CodeLens, press OK, i see the extra space required for the CodeLens information and than it disappears and when i look at the options again it is diabled. Driving me nuts.
Approaches
Deleting caches/configurations. Clean start without Extensions work. Normal start without ReSharper works. Reinstall ReSharper + deleting cahces -> False behavior
Solution
Unter Extensions - ReSharper - Options - Environment - Performance Guide was "Disable CodeLens for all languages" set to "Fix Silently". Set to Ignore -> WORKS!
hope this helps someone
I had the same problem, but one's of my colleagues who has the same development environment than me, doesn't have it...
The only one difference between our both environment was the quantity of RAM. There is 10GB allocated to his VM, and on mine, there is 6GB allocated. Since I upgraded the quantity of RAM allocated to my VM to 8GB, all my references are shown !
Installing Update 1 for Visual Studio 2015 fixed the problem for me.
Download Update 1
After reading the answer to this Stack Overflow question CodeLens only showing references? I decided my problem with Codelens was I was running Visual Studio 2015 Update 1 but was using Team Foundation Server 2012. I upgraded to TFS 2015, which upgraded in place and didn't require any new settings or URIs to be connected to Visual Studio as before. Then I reloaded my solution - but I still had the issue where it just said "– references" everywhere. I closed Visual Studio, started it again and reloaded my solution and finally I saw the correct reference counts as they used to show.
I found on the new VS 2015 update 3 it happens on a large class in a medium level solution 10+ projects and has nothing to do with circular references, a bad SUO file, or other things. It appears just deleting the temp file location(as mentioned already), closing VS and then reopening and hitting 'ALT+2'(forcing a reference find for Code Lens) made it magically work for me.
It also appears in some solutions and projects Visual Studio will create an old referenced suo file in .vs folder. I don't know the exact rhyme or reason, but it could be created in my case and the CodeLens worked again. It could potentially be a Visual Studio options is somehow referenced in projects under source control. As I know this happened with an older solution I have upgraded many times that was under GitHub control and it does have an .gitignore file(ignore files could change depending on source control). Suffice to say I have had similar things happen with other techs in the past when there is a lock on a source control file that should be updated and won't update. Simple answer is to add to an ignore and delete the settings file.
I have Visual Studio 2017 Professional on Windows 10.
I have observed this under several circumstances:
MicroSoft decided I needed some critical update for Windows and it installed while I was working - causing some of the VS components to crash.
Visual Studio update was received in background.
Some component of Visual Studio crashed - not the VS just some attached feature (did not note exactly which one)
No known cause.
In each of these cases I did in order (sometimes it worked after each of these)
Build / Rebuild solution
Build / Clean Solution
Close and Restart Visual Studio
Remove Symbols cache, restart VS
Close BOTH VS and SSMS and restart them
Close VS and Restart Windows
Close VS, force all pending Windows updates to load, restart Windows
In options, Uncheck Codelens/apply and re-check/apply (OK button)
I tried most of the solutions above without luck, as I also saw this problem. On top, certain newly added classes were showing up as white/black (regular text) in Visual Studio.
Changing to Release typically helped, but wasn't a long-term solution.
However, this helped on both issues - verified on another machine. Maybe some of the steps can be left out.
Close all document tabs
Clean solution
Right click on solution, click "Enable Lightweight Solution Load"
Close solution
Reopen solution
Right click on solution, click "Disable Lightweight Solution Load"
Close solution
Reopen solution
Rebuild
Explicitly enable CodeLens in the workspace settings.json:
// show code lens on editor
"editor.codeLens": true,
Verify that the following properties show on the editor:
// inline count of reference for classes, interfaces, methods, properties,
// and exported objects
"typescript.referencesCodeLens.enabled": true
I could fix my problem with C# CodeLens and Omnisharp.
My C# extension was 1.25.0.
What I did to fix my problem:
C# extension -> Unistall -> Install another version -> Version 1.24.4
After that in the settings I searched for "omnisharp: use global mono" and set it from "auto" to "alwayse".
Then restart Omnisharp and wait for it to compile and show references.
Removing data from %temp% folder resolved my issue in VS 2022.

Why does it take sooo long to load my solution in Visual Studio?

We have a really big solution with more than 200 projects and thousands of files. Despite of that the solution used to load pretty quickly in Visual Studio 2010 as well as 2012. However, after copying the whole SVN repository to another location, loading and closing the solution suddenly took extreeeemly long. (I am talking about 30-60 minutes here!)
I found a solution myself and I wanted to share it here, hoping that it might save someone quite a few hours of research and staring at the "Preparing solution..." dialog.
When inspecting the devenv.exe process with Process Monitor, I found out that it is pretty busy with accessing the .svn directory. Here is what I did (and this somehow solved the problem):
Kill Visual Studio
Open Visual Studio without loading a solution
Disable AnkhSvn as Source Control plugin (Tools->Options->Source Control->Plug-in Selection->None)
Disable "Document Well 2010 Plus" (VS2010) or "Custom Document Well" (VS2012) in Productivity Power Tools (Tools->Options->Productivity Power Tools) - I read that somewhere and it might have helped as well...
Close Visual Studio
Delete the solution's *.suo file. This is located in the same folder as the solution itself. NOTE: You will lose several settings for your solution, like currently opened files, breakpoints, bookmarks, current solution configuration & platform (e.g. Debug x86) etc.
Restart Visual Studio
Load the solution - it was much faster now!
Close Visual Studio
Open Visual Studio without loading a solution
Re-enable AnkhSvn and the "Document Well"
Restart Visual Studio
Open the solution - it was still loaded in seconds!
I do not know which of these steps actually solved the problem. Probably, not all these steps are required, but I did not want to reproduce the problem to find out which steps may be omitted. :)
None of those helped me, what I did... I watch with ProcMon of sysinternals, filtering for devenv, and I saw a lot of entries of fussionlog. I had enabled fussionlog for debugging purposes some weeks before and didn't think in disabling it. I just had to disable fussionlog and the solution opened faster.
You can open the Visual Studio in the Safe Mode, and then check your plugin and source control settings after opening the project.
Safe Mode means "Starts Visual Studio, loading only the default environment and services."
How :
devenv /SafeMode
Or according to your path
"C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\devenv.exe" /SafeMode
source : https://msdn.microsoft.com/en-us/library/ms241278.aspx
In my case, the following worked without any of the intervening steps suggested:
Kill Visual Studio.
Start Visual Studio directly (i.e., not from the .sln file).
Then, from within Visual Studio, open the solution.
In my case this was all it took to make the problem solution load quite quickly, without the need for me to change any settings or delete any files.
fwiw, I realize this is a late entry, but I found that simply removing (deleting) my large number of breakpoints resolved the excessive load time and compile time.
This action reduced the size of the .suo file from 214MB to 977KB. Let VS handle the .suo file itself.
Compiling and loading now takes < 1 minute instead of 5-10 minutes for a solution with 35 projects. Visual Studio 2012 Pro, update 4.
None of the other answers worked for me. CI compile times were fine, but loading my solution in Visual Studio was taking almost two minutes. VS would then operate just fine until I closed and opened the solution the next time. Different versions of VS all showed the same problem and both safe mode and deleting the suo didn't help.
I ended up following the advice in http://geekswithblogs.net/akraus1/archive/2014/04/30/156156.aspx to use Windows Performance Recorder to instrument VS and find the problem. By looking in Windows Performance Analyzer under the "CPU Usage (Sampled)" section and adding the "Stack (Frame Tags)" column, I was able to dig into the usage of devenv.exe.
Turns out the hot path by count had Microsoft.VisualStudio.Platform.WindowManagement.ni.dll 23 calls down, and below that eventually Microsoft.VisualStudio.ServerExplorer.dll and Microsoft.VisualStudio.Data.Package.dll. That pointed me to look in Server Explorer in the UI and open the Data Connections tab. There I found hundreds of mistakenly added connections that came from the debug web.config's ConnectionString section. Removing those from web.config reduced the load of that individual project from 90+ seconds to almost instant.
I have a different cause for the slow loading of the projects.
My situation is utilizing Git and found that even switching branches was slower than it should be with project load.
Solution: Run Visual Studio as Administrator
Reason: Something with the Corporate laptop is not providing the needed Git tool access (it doesn't recognize that a git repository is in use).
I have not seen any issues with Git or my personal access to any of the project files or Git objects.
I tried the above, but it didn't solve my problem.
Here's how I got around this problem, hopefully it will work for some of you as well:
Open Visual Studio 2013 with no solution.
Create a new C# Console application and save it.
Close Visual Studio.
Reopen the Console solution created in step 2.
Close Visual Studio.
Reopen the solution that was previously hanging on the Preparing Solution dialogue. Mine opened right away, no more hanging.
Using Visual Studio 2015, I ended up creating a new solution, adding the existing projects.
Deleting the *.suo from gehho's answer helped in the past, but didn't help me in this case. There's also another .suo file in a hidden .vs folder at the root of the solution.
There are other answers here for Visual Studio 2015 Visual Studio 2015 is extremely slow
For my case it was due to TFS issue. It thinks that there are more than 5000 pending changes.
The fix is to force TFS to recheck. Go to Team Explorer -> Source Control Explorer and do "Get Latest" on the projects that have pending changes. For things that are already matching TFS, Visual Studio will actually not download anything to your PC. For things that are different with TFS, Visual Studio will let you know and ask you to reconcile the difference.
This is VS 2019 Professional.
In my case there were <import ...> entries in the project files that pointed to
paths no longer available making the loading of the solution hang indefinitely without any form of information give (Shame on Microsoft!).
I encountered this problem only recently (Mar 2021), using VS 2019. It literarily takes 30+ seconds to load the file (each).
It only effects the Layout files. I believe it could be to do with the links within the files. I have not had time to investigate them.
However, I am writing this to suggest that regardless of the cause of the problem, a simple solution is to right click on the file and open it with Notepad to get your work done.

Visual Studio 2010 intellisense stopped working

I've got a small problem with the VS2010. I installed Resharper and soon after my installation period has expired, My Visual Studio 2010 Intellisense stopped working. Its very hard to work without Intellisense. It doesn't even show the member properties even . I tried doing devenv.exe /ResetSettings and I end up with an error saying:
it is not recognised as a internal or external command, operable program or batch file.
My solution
I don't know how people are solving this but I just solved my above problem by resetting the Vs settings. Tools-->Import ExportSettings-->selecting the reset all settings and following the wizard .
By doing this of course I lost the little settings I made just like adding line numbers and stuff, but I did that again.
Not sure if this is the ideal solution for people looking for an answer, but just helped me to get the Intellisense in the first place which I was actually looking for.
This worked for me.
http://miguelmoreno.net/post/Intellisense-not-working-in-Visual-Studio.aspx
In Visual Studio select Tools > Options > Text Editor > All Languages. Ensure that the checkboxes in the Statement Completion section are actively checked (not grayed out).
For risk of sounding like tech support:
Reboot your machine and check if Intellisense is back, else try devenv /ResetSettings again.
I tried to reboot and devenv.exe /resetsettings.
What actually worked for me was the following:
Goto Tools > Options > Resharper
Suspend Resharper
Resume Resharper
No application restart or PC reboot or anything required after that.
Found here: http://geekswithblogs.net/GruffCode/archive/2010/11/09/resolving-issue-ldquoresharper-auto-completion-live-templates-and-intellisense-stop-working.aspx
Saving my project then restarting VS worked for me.
I accidentally had two of the same file open in the IDE. After closing one of them, intellisense started working again! This is how you can reproduce it:
Drag a tab onto your desktop, then open the same file by double clicking it in the Solution Explorer. You now have 2 of the same thing open. You can now drag that floating window back into the IDE as a tab and now you (unfortunately) have 2 of the same file open at the same time. You can only edit the original one and the other one will drive you crazy.
#Ronald McDonald, I tried that solution, but everytime I go back in, the Statement Completion options are reset, so that the boxes are filled, not checked (i.e. on for some languages, off for others). I'm guessing that it's ReSharper responsible?
For anyone else having this problem, if the above solutions don't work, and you have ReSharper, give this a try:
Reset key mappings in Visual Studio: Make sure only one instance is running. Tools -> Options -> Environment -> Keyboard -> Reset.
Restore ReSharper keyboard shortcuts: ReSharper -> Options -> Environment -> General -> ReSharper keyboard shortcuts. Close Visual Studio.
It's too early to tell, but I think (hope) that this has worked for me. I keep losing not only Intellisense, but undo/redo stops working (even greys out in the Edit menu, until I reopen the menu a few times), along with copy/paste and most (sometimes all) Ctrl+ keyboard shortcuts. I've had this problem for years, on different computers, and I'm pulling my hair out trying to fix it. I really hope this one finally worked!
First check in VS tools-> options-> editor -> statement completion is checked (not grayed out).
Then follow this procedure:
close all open files in the VS IDE.
Save & restart VS.
Make sure the file you are writing into is included in the project (and not excluded by mistake)
If this does not solve the problem, close VS & try from the command line running: devenv /ResetSettings
else try installing the hotFix: http://connect.microsoft.com/VisualStudio/Downloads/DownloadDetails.aspx?DownloadID=26662
cheers
Change the path location for the project . If it exist in some folder then place it into another.
This will solve the issue
Intellisense stopped working. Tried the methods suggested here to no avail. Noticed it was only affecting only the current file. Closed Project, deleted the .suo file and restarted project. It is now working for all files. :)
If using ReSharper:
ReSharper / Options... / "Clear Caches".
Quit and restart Visual Studio.
I found that I had mistakenly uninstalled SQL Server Compact 3.5 SP2.
Re-installed, then set Options->TextEditor->Advanced->Disable Database = False
worked for me.

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