VB6 IE frame / WebBrowser causing NT.dll error - vb6

We have a legacy VB6 application which has worked just fine on Windows XP Professional SP 3 until just recently when we added an IE frame control so that we could display static local HTML files on a form. And, it works fine until I go to close the application. And, then it reports the following error message (consistently):
Faulting module ntdll.dll, version 5.1.2600.5755, stamp 49901d48
Here's the reference in the Visual Basic project file:
Object={EAB22AC0-30C1-11CF-A7EB-0000C05BAE0B}#1.1#0; ieframe.dll
And we use it by performing the following actions:
Development machine is running Win7 + Vb6 IDE.
Add a component reference to the "Microsoft Internet Controls" located at C:\Windows\SysWow64\ieframe.dll
Place a control on the form at design time.
Show that form modally by calling Form.Show vbModal The error happens when I use the default form instance frmMyForm.Show vbModal as well as when I use a local instance Dim MyForm as New frmMyFormMyForm.Show vbModal
Call WebBrowser.Navigate "staticPage.html"
When the user presses a button, the button click event returns the user choice and the form is disposed of.
Exit the application -- Here's where I get the error.
I've been looking all over the web, and haven't been able to find a whole lot of people still trying to use VB6 in this way. So, I'm wondering if someone might be able to help me on stackoverflow. Any help is much appreciated!
[Update] And, the plot thickens. I made a sample application with just that web component in order to make sure that it was causing the error. But, I didn’t experience the error when it closed like I was when exiting our existing/legacy vb6 application. I'll do a bit more investigating.

A follow up to this in case any runs into the same issue (the original poster and I were coworkers at the time)...
The application was using the VBCorLib library, and some of its string manipulation classes utilized direct memory access incorrectly. Read more at this VBCorLib forum post.

It turns out that the issue was that I was trying to delete the temporary file that the browser had loaded. It works now that I've moved that delete file code to the form unload event.

Related

VB6 application won't run in some computers, in others it runs fine

I have a VB6 application, the installer is compiled using INNO Setup.
The installer runs fine. But in about 10% of computers when the user clicks the Icon to run the installed app, it doesn't start, no error message, only a Beep sound.
This is happening on XP and also Win 7.
I develop in XP and Win 7 and the application works OK, so I haven't been able to reproduce the issue.
The installer registers all ocx and dlls needed (afaik). (Well not completely all, it assumes MS run-time components should be there, but I guess an error message should show up if something is missing)
I was thinking some kind of user permissions, UAC, but even users in the admin group have had the issue.
Could you point me to what possible issues to look for and test in order to patch the app.
Thanks!
[FOLLOW UP]
Thanks to the tips, found out the manifest is causing the problem. I use it to make the controls look better:
http://www.vbaccelerator.com/home/vb/code/libraries/xp_visual_styles/using_xp_visual_styles_in_vb/article.asp
Now I'm trying to discover why. I have another application with the same manifest and that one works ok.
Haven't been able to get feedback on the event viewer yet.
The "beep crash" often points to an error in an application manifest such as an XML syntax error or namspace conflict. Event Logs will often provide a hint about this.
But I've found that people often try to use the Common Controls 6.0 Library without ensuring proper library loading sequence.
Before any Forms are openend you should load shell32 and then comctl32. The easiest way is a couple of no-op calls in Sub Main:
Option Explicit
Private Declare Sub InitCommonControls Lib "comctl32" ()
Private Declare Function IsUserAnAdmin Lib "shell32" () As Long
Private Sub InitCommonControlsVB()
IsUserAnAdmin
InitCommonControls
End Sub
Private Sub Main()
InitCommonControlsVB
Form1.Show
End Sub
Without this your program will usually work fine in Vista or Win7, but will fail on some XP service pack and patch levels. Part of this is due to changes over time in the Fusion subsystem that handles SxS activation and comctl32.dll patches.
Ignore those saying you need to call InitCommonControlsEx(), it isn't necessary unless you are constructing and using Win32 controls directly instead of VB6 and COM controls.
A few things to try to narrow it down:
Check the Windows Event Log for crash events
Check the Windows Event Log (in the Application section) for crash reports from your application. You can quickly get to the log viewer on Windows XP by clicking Start > Run, typing eventvwr and pressing Enter. On Windows 7, you can type "event viewer" in the search box that is in the Start menu. You can filter the events to only show error events from your program.
You might find a few error events on one of the computers where this problem has already occured, because it sounds like the error reporting feature is turned off on these computers (in which case "hard crashes" like access violations are logged in the Event Log instead of displaying an error dialog to the end-user, as long as a debugger isn't installed on the computer).
Make sure "Error Reporting" is turned at the OS level
As mentioned in the previous section, it sounds like the error reporting feature is turned off on these computers. In that case, a crash won't display any kind of message to the end-user at all and the application will just vanish suddenly. In Windows XP, you can check this setting (and turn it on) as follows:
Right-click "My Computer" and select Properties.
Open the Advanced tab and click the Error Reporting button.
Select the Enable Error Reporting option.
Click OK to all the open windows.
Add trace code to your application
You could also add some trace code to your application's start-up code, such as code to display a message box or write a message to the Windows Event Log or to a log file as soon as your application starts (for example, in the Form_Initialize event of your main form, or in a Sub Main routine).
This way you will be able to tell whether your application is crashing before or after the VB6 runtime is loaded: if you try to start the application and it disappears/crashes, and your startup message isn't logged, then you know it's crashing before it even has a chance to get to your application's startup code, which could indicate that a dependency of the VB6 runtime or the VB6 runtime itself is not installed properly.
Note that Windows XP and Windows 7 both ship with the VB6 runtime pre-installed, but it's possible for misbehaving installers to overwrite or remove files that are part of the VB6 runtime.

Why is the OnComm event of MSCOMM32.OCX in Access 2003 VBA missing?

I've dropped the VB6 MSCOMM32.OCX (Microsoft Comm Control 6.0 (SP6)) on to a VBA form. I had to apply a Microsoft Security Update KB926857 to VB6 to get the control to drop on the form because a Windows Update set a kill bit on the older version.
When I look at the object's events in VBA I do not have "OnComm" available. I can get it in VB6 by double clicking its icon (a phone) but not in VBA. Importing it in Delphi shows OnComm as the only event handler.
I know the control is registered properly and licensed.
I've done it a couple of years ago with the older control, but has anybody done this lately?
Available Events: OnEnter, OnExit, OnGetFocus, OnLostFocus & OnUpdated
I discovered independently that HK1's suggestion was correct. I created an event handler that looked like this
Private Sub MSComm1_OnComm()
Nothing needed to be done to the object properties to link it to the routine.
In the form load event I placed an MSCOMM1.PortOpen = True. I scanned a bar code and presto it worked.
Why this is treaded differently than other events I do not know and how/where it is documented is a mystery.
This Microsoft site has helpful information on handling the data properly and is what I used for the test.
http://support.microsoft.com/kb/194922

Start Internet Explorer 8 in a separate process using vbscript

Due to the recently added "feature" in IE8 where new windows are automatically associated with a single session, some of our code is behaving erratically.
This is because a separate app would launch a new IE window when it was activated, and once the user was finished, close the window. This worked fine in IE7 because the session information in the windows stayed separate. However in IE8, since the session is shared among IE windows, we find that the "pop up" app would corrupt the session on the first app.
I have read about the nomerge switch, so that is a workaround, but I was wondering if there was a way of working the solution into the "CreateObject" of vbscript; i.e:
Dim ieWin As Object
Set ieWin = CreateObject("InternetExplorer.Application")
Is there a way of sending parameters when calling the CreateObject function?
No, there's no way to use COM to create an IE instance that specifies this behavior (or any of the others, e.g. InPrivate, No Add-ons, etc). The only thing you can do is create an automation instance that defaults to MediumIL using the CLSID provided for that purpose. http://blogs.msdn.com/b/ieinternals/archive/2011/08/03/internet-explorer-automation-protected-mode-lcie-default-integrity-level-medium.aspx
If you have control over the web application you are loading with your IE window you can set it's session to "cookieless" (http://msdn.microsoft.com/en-us/library/aa479314.aspx) which will avoid the issues you're having with multiple instances.
The solution we ended up going with, although it's more a work around than anything else - was assigning a new url to the popped up window.
Previously, it worked as follows:
Call centre agents would be using our internal app for other duties
e.g. "http://internalsite/somepage.faces" on a day to day basis.
When they got a phone call, a third party app would fire up
"http://internalsite/customerdetails.faces". This caused the issues mentioned above.
The solution we went with:
We assigned "http://internalsite/customerdetails.faces" it's own url e.g."http://customerdetailminisite/customer.faces".
This way the call center agent could keep their main window open for other stuff and still be able to handle calls when they came in.

Another knack on the "Dialogs must be user-initiated" Security Exception in Silverlight printing

I get the infamous "Dialogs must be user-initiated" Security Exception when I try to print some stuff in Silverlight. As you can see, the dialog is as user-initiated as can be:
John Papa couldn't help me much out neither, because I don't have any breakpoint set. Mr MSDN thinks it could also be that I'm just taking too long, but this is a demo application just as simple as can be.
Any ideas? I guess it's a Visual Studio quirk, maybe some extensions interfering, as things seems to work when I launch the application outside of it. I first thought maybe the Code Contracts are interfering with their IL weaving, but they are deactivated for this project.
Update: This is just a simple Silverlight application that runs locally from the file system. When I do "Start debugging", Visual Studio creates a hosting HTML file containing the Silverlight app in the Debug resp. Release folder of the project, launches the Internet Explorer with that HTML file and attaches the debugger to it.
Update 2: I also get the same error when I create a web project to host the Silverlight app and create a virtual directory for it on IIS.
I might also want to add that I don't have problems with printing in other Silverlight projects regardless of their hosting scenarios.
Update 3: I downloaded FireFox and it works, I don't get the error when I debug with it. So it seems to have to do with my IE8. I uploaded the solution:
http://dl.dropbox.com/u/10401470/Code/Demos/PrintingDemo.zip
I wonder if anyone can reproduce?
Anyone got an idea to which team I should file a bug report? Silverlight team? IE team? VS Debugger team?
I'm able to reproduce this. You have handled the Click twice, once in XAML another time in code. See your MainPage.xaml
<Button x:Name="PrintButton"
Content="Gotta print 'em!" Margin="8"
Click="PrintButton_Click" />
Don't feel bad about it. I did it last time through a misplaced Print inside a loop.
I've also experienced this strange behaviour. A standard button click event immediately invoking an OpenFileDialog. It would frequently generate the same error when being debugged but would eventually be coaxed in to working when the button is clicked several times.
However when built as a release (or perhaps simply by running the same Xap without a debugger attached to the browser) the problem would go away.
Try to remove
if(SightPaleceListBox.Items.Count > 0)
I had the same problem and found out that the reason was this following line:
cnvsMain.Children.Remove(PrintPagePlaceHolder);
cnvMain is on the page that the user pushed the Print button on (I was trying to remove it from that page in order to add it to the canvas that I was going to print).
My tip: try to comment rows one by one, until you find what row causes the problem. Than try to work around it.

adding/removing a file in VS2010 causes "WebDev.WebServer20.exe has stopped working" error

This is driving us crazy... In VS2010, MVC2 projects, not all projects.... both on a project that was upgraded from 2008/mvc1 and on a brand new project created within 2010/MVC2, we have the following behavior:
1) develop as normal..
2) hit F5 or CTRL-F5 to open up a browser
3) works great!
4) add a CSS file (or JS file or any file, or remove any file) in the project
5) immediately the dialog pops up "WebDev.WebServer20.exe has stopped working"
You have to close the program, and "F5" again - and all is right with the world...
Say we then modify an existing css file. No problem. But adding or removing one, immediate crash.
It seems like the development webserver is "locked on" to the project file and when it detects a change, it dies.
The Event Viewer is pretty unhelpful. The following is logged:
Faulting application WebDev.WebServer20.exe, version 10.0.30319.1, time stamp 0x4ba204ca, faulting module KERNEL32.dll, version 6.0.6001.18215, time stamp 0x49953395, exception code 0xe053534f, fault offset 0x000442eb, process id 0x%9, application start time 0x%10.
This is happening on all of our developer workstations, which include some with Windows Sever 2008, some with Windows XP, and some with Windows 7. All are running VS2010 Premium with ReSharper.
Also, the same thing happens on projects which target the 4.0 framework, only the error message referrs to WebDev.WebServer40.exe instead.
Google has revealed nothing. We've already tried "setting a static port" instead of a dynamic port - no help.
Please help if you can.
So, as it turns out, the problem was due to a certain use of MVCTurbine and StructureMap, but it seems likely that the problem would also occur with other IOC Containers, not just StructureMap.
The author of MVCTurbine has expressed that the fix will be in version 2.2 of that product.
In the meantime, one extra line of code in your Global.asax will solve this problem:
//VNEXT: after Turbine 2.2 we wont need this line anymore...
protected override void ShutdownContext() { CurrentContext = null; ServiceLocator = null; }
This article shows the particular use case we were addressing. The "normal plain vanilla" use of MVCTurbine and StructureMap would not have this problem.
Obviously, great thanks to Javier for being so responsive to help requests!

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