Samrae welcome to our community!
You are crashing at line 279 in AbError.clw which is 12799 is ErrorClass.Init PROCEDURE()
The C0000005 would indicate that is null.
Do the Project Defines have _ABCLinkMode_ and _ABCDllMode_ ?
FishData.DLL would have =>1 and =>0
Fish.EXE would have =>0 and =>1
@jslarve - I found backslash underscore is required escape to get just underscore in Markdown without italics