This application requested the runtime to terminate it in an unusual way

[John E]

Does anyone happen to know what kind of programming problem causes the above error dialog? I've always been curious about it.

AFAIK it isn't cause by an unhandled exception (an unhandled exception seems to have its own dedicated error dialog). Likewise, I don't thnk it's caused by an access violation. That situation also seems to have a dedicated error message ("the memory at address 0xNNNNNNNN could not be read").

For years I (wrongly) assumed that it was caused by calling exit() with a non-zero status code - but that isn't true either (I just tried it).

So what kind of condition triggers a "request to terminate in an unusual way"

[Igor Vartanov]

This may happen when you have some issue, e.g. an exception fired, during initialization of global objects. In this case, as you may understand, the dialog appears when you start your app. Is this your case?

[John E]

Hi Igor, you're in the right area but that's not exactly what's happening....

To give some background, I'm converting an app that was written by somebody else. The app was originally written for Linux and I'm converting it to run on Windows. I've often done this kind of thing (for the same client) so we're both experienced with it by now.

The app runs fine on my dev system. About 10 days ago I gave a copy to my client and it ran fine for about a week. Then it mysteriously started giving this error. The app starts okay but the error happens when they try to load files (any files). The loaded file appears in the app's GUI - but about 5 seconds later, they get this message appearing! They do have MSVC on their dev system - but they're Linux developers so they don't have much experience with MSVC. We're setting up UVNC so I'll be able to debug it remotely. In the meantime I'm trying to get some kind of "heads up" on what could be causing it.

I've experimented this morning with some other possibilities - such as freeing / deleting unallocated memory - but those operations don't produce that particular message either.

I've a hazy memory of seeing this issue once before when I'd mistakenly used mixed 'C' runtimes (i.e. I'd accidentally linked a Release module to a Debug DLL). But I doubt if that'll be the cause in this case (given that the app worked for the first week). My guess is that they've somehow deleted one of the app's components (a config file maybe).

Things should become clearer once we have UVNC set up.

[Igor Vartanov]

MS has previously admitted a few similar issues with msvcrt. Try this and this article.