>I have a C++ client application that accesses a VFP EXE COM server to retreive some data from a Firebird database.
>The VFP EXE COM server exposes several VFP Procedures. The C++ Client is able to work with all of them except for one.
>I have a C++ Try...Catch around the call to the COM server for this particular procedure. The Catch clause catches the COleDispatch Exception.
>I have put a call to OutputDebugString on entry to this procedure to try to identify where the exception is occuring. I never get the output from that call. So, the exception must be occurring between the call to the COM server procedure, and entry to the procedrue.
>COM servers are so difficult to debug.
>This was all working before. I made a minor change in one of the other procedures in the COM server. That procedure is still working fine. I made no changes in the procedure that is failing.
>Any idea?
>Thanks,
>Jim


Do a diff on your changes (WinMerge utility) and see what was affected. Put it back to its old state and verify that it's working properly there. Introduce components of your change one by one until you find the cause.

Access Violations are almost always the result of invalid pointers, or attempted null pointer access. There are additional flags in Visual Studio's debugger you can set to catch additional exceptions. You might try it there and see if you can catch it by using two instances of the debugger. One to connect to your client process, the other to connect to your com server process.

Just a few thoughts.