try/catch and __try/__except blocks are setting per thread exception frames , so your Fortran dll may spawns another threads that may throw the unhandled exceptions you are faced. Try to set a proccess wide exception filter that will exceutes as the last recover to the unhandled exceptions that may be thrown by your dll. the key function is the Win32 SetUnhandledExceptionFilter function. I hope it works for you. AbuMalek

No you don't need to wrap it with a com object, simply you need to keep your data structure as a global variable to the dll module then provide a code that manipulate that structure with a multi-threaded-safe fasion and you are done. if you want to avoid writing syncronization code you can rely on the sahred property manager as daniel advised. AbuMalek

Hi All, I'm trying to set a top-level exception call-back filter inside a com+ application server. Although SetUnhandledExceptionFilter seems to succeed, that it returns the previously installed filter correctly, my filter never been called. of course I'm trying to detect the call in a (release mode) through a simple code that creates a log file to be filled later with the proper informations I need for recovering.When calling the filter from a __try/__except(MyFilter(..)) block, the filter code executes correctly, but when generating a purposly unhandled exception the file is never been created. Any idea? Regards. AbuMalek