I have been looking at the build/startup log when starting my app on the dev machine.

I noticed that right before the error it is loading and unloading a PDF viewer my app uses

'DMS DataEntry.exe': Loaded 'D:\...\bin\Debug\PDFXCviewAx.dll', Binary was not built with debug information.
'DMS DataEntry.exe': Unloaded 'D:\...\bin\Debug\PDFXCviewAx.dll'
A first chance exception of type 'System.BadImageFormatException' occurred in System.Windows.Forms.dll

this is the activeX pdf viewer from Tracker Software (http://www.tracker-software.com/) i am using there. so i am thinking maybe that that viewer has something to do with my error.

But 1st the entries before the error look normal
and 2nd how would one go about having 2 activeX versions on a vb.net form - a 32-bit and a 64-bit version?




>To be clear - did this occur when running the skeletal project I suggested. If not then try that. Is so try this:

Module Module1
>    Sub Main()
>        Console.WriteLine(IntPtr.Size.ToString())
>        Try
>            Dim em As System.Linq.ParallelExecutionMode = System.Linq.ParallelExecutionMode.Default
>        Catch ex As Exception
>            System.Diagnostics.Debugger.Break()
>        End Try
>        Console.ReadLine()
>    End Sub
>End Module

Console write should be '4' if running in a 32-bit environment, '8' for 64-bit. The catch may give you a bit more information on the exact nature of the problem if in the IDE (check for inner exceptions)
>
>FWIW I think the path you mention is normal for the framework DLL's - but if the exception occurs in the line that uses System.Linq I don't know there System.Windows.Forms.dll comes into it ?
>Also, FWIW, I ran the above code on a 64-bit WIN7 machine in both 32 and 64 bit modes with no problem.
>Where did you find any references to problems with System.Windows.Forms.dll on 64-bit ?
>
>
>>Before I do that it occured to me that i am developing this on a win2003 64-bit machine. So instead of just building and then installing on another pc i run it right out of VS2010.
>>
>>There i get the following error running as AnyCPU:

>>A first chance exception of type 'System.BadImageFormatException' occurred in System.Windows.Forms.dll
>>'DMS DataEntry.exe': Loaded 'C:\Windows\System32\version.dll', Cannot find or open the PDB file
>>An unhandled exception of type 'System.InvalidOperationException' occurred in DMS DataEntry.exe

>>some research suggests that there is an issue with 64-bit version of System.Windows.Forms.dll. I looked where the file is comming from (in the properties) and it comes from "C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\System.Windows.Forms.dll" - notice the "x86" - but so do most of the other dlls listed in the references.
>>
>>I also tried to add an exeption routine to my app - ran into problems. But I think i start a seperate thread for that.
>>
>>Thanks.
>>
>>
>>
>>
>>
>>>As per the namespace the ParallelExecutionMode enum *needs* System.Linq. The question was whether use of just that line also causes an exception on the XP/64 machine. See if this one-line project will run:

Module Module1
>>>    Sub Main()
>>>        Dim em As System.Linq.ParallelExecutionMode = System.Linq.ParallelExecutionMode.Default
>>>    End Sub
>>>End Module

Also, as mentioned earlier, look at catching unhandled exceptions in code - that will give you more information on the exception details.
>>>