I wouldn’t be surprised if a compiler used the same method to bring program source into memory for compilation as SEU does for editting. They could easily clobber each others’ memory work spaces.

First thing I would try is to break the call to the compiler out into a separate program. My SEU exit program would call the new program to do compiles. The new program would run in a different activation group, either a named AG or *NEW.

It might not solve the problem, but it might produce enough of a different error to help see the problem.

Tom