COM...the gift that keeps on giving

Here are some more things I learned today and all of these parts are related to the same program halt....

TODO: <File description>

I don’t know exactly what triggers the MFC error message box with the text, "TODO: <File description>". But I now know that I have a good reason to fill in all the VS_VERSION_INFO resources in my projects. Under some circumstances Microsoft pops up the message box below, obviously I couldn’t find any documentation that tells me exactly when Microsoft will do this, but I know it can happen.



To identify which part of the project triggered the error, update the FileDescription field in all the VS_VERSION_INFO structures in all your projects. That way when it goes you’ll know what assembly/dll was involved.

In Visual Studio open your project's the Resource View and under Version you’ll see VS_VERSION_INFO, change "FileDescription" to something unique.

EEFileLoadException

I haven’t exactly tracked down why this exception is being thrown. Microsoft doesn’t document it. But Microsoft does document the exception FileLoadException. Considering that I’m calling a managed assembly through an exposed COM interface from an unmanaged C++ executable, the error does fit. The description for FileLoadException is "The exception that is thrown when a managed assembly is found but cannot be loaded."

For some reason the description triggered some dormant brain cells, probably hanging around from when I was younger, which caused me to look in my Event Log. So I opened Event Viewer and I found that I had a .NET Runtime error that corresponded to the time I got the EEFileLoadException. Hmmm.

.NET Runtime version 2.0.50727.42 - 
Fatal Execution Engine Error (79F97075) (80131506)

Okay, this is more information but...what does it mean? Searching on the number 80131506 from MSDN of course doesn’t get a hit (if you hear a really loud sucking sound, that would be Microsoft search...sucking!)

First-chance exception at 0x7c81eb33 in MonteCarloPiApp.exe: 0xE0434F4D: 0xe0434f4d.

I also got a message box with the above error. Not much information available for this one, but I did find some recommendations about not running the application inside the debugger. So, I launched my program outside the debugger, got the "TODO message" box and selected the "Debug" button, which launches the debugger and sweetness... I get a "COMException was unhandled" error with an HRESULT of DISP_E_MEMBERNOTFOUND and a nice stack.

System.Runtime.InteropServices.COMException was unhandled
Message="Member not found. (Exception from HRESULT: 0x80020003 (DISP_E_MEMBERNOTFOUND))"
Source="System.Windows.Forms"
ErrorCode=-2147352573
StackTrace:
at System.Windows.Forms.Control.MarshaledInvoke(Control caller, Delegate method, Object[] args, Boolean synchronous)
at System.Windows.Forms.Control.Invoke(Delegate method, Object[] args)
at g.a(Delegate A_0, Object[] A_1)
at Digipede.Framework.Api.DigipedeClient.d(JobStatusEventArgs A_0)
at Digipede.Framework.Api.DigipedeClient.f(Object A_0)
at System.Threading._ThreadPoolWaitCallback.WaitCallback_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback(Object state)

That’s something I can work with.

Updated formatting problem