Symptoms
Win32 processes can install an unhandled exception filter function to catchexceptions that are not handled in a __try/__except block on a process-widebasis. When debugging such a process, you find that the unhandled exceptionfilter is never executed, even when you put a breakpoint inside it.However, when the process is not being debugged, its unhandled exceptionfilter is called as expected.
Resolution
When called from a process being debugged, the UnhandledExceptionFilter()Win32 API function does not call the application-installed unhandledexception filter.
Note The UnhandledExceptionFilter() API determines whether the process is being debugged. If the process is being debugged, the UnhandledExceptionFilter API passes the exception to the debugger. Then, the UnhandledExceptionFilter API calls the unhandled exception filter for the process.