Run your application in the debugger and find out what is throwing the exception. Fix it.
That might not look very helpful, but with the limited amount of information you supplied I would say it's the quickest way.
Edit: since it doesn't crash in the debugger, I suggest making the executable create a crash dump. You can load that into the debugger and it should help you find the fault the next time it happens.
Here are a couple of functions that should help you with that:
SetErrorMode[
^]
SetUnhandledExceptionFilter[
^]
MiniDumpWriteDump[
^]