Robert,

The fixes that worked first time.

I added MxGetMethodAddress and the two structures, MxLinkRec and MxClassDR exactly as you had them in your email (copied them) into the top of the MxClassVAList.c file along with the #includes at the top.

I then removed from MxClassVAList.h the function prototype for MxGetMethodAddress because it is now in the .c File.

Compiled and executed on the first try. What a relief.

Put simply it worked first time only having the MxClassVAList.incl as the FB file in the Project and MxClassVAList.c & MxClassVAList.h within the same folder but not shown in the project.

Using the second approach of making all of the C files FB files then using the if def _PASSTHROUGH approach will undoubtedly work the first fix above did the trick beautifully.

Thanks so much for you help. Maybe others will find some benefit in all of this as I did.

Max Taylor
The MaxClass Guy