When running a GUI C application, the following 2 different error messages may have the same root cause:
'Could not register IEFWINOW class'
'No DBMS Stub Executable has stopped working.'
The errors are caused by having a Gen 8.0 deployment directory successfully running and then creating Gen 8.5 Load Module DLLs and putting them into the Gen 8.0 directory. A flow from a 8.0 Application DLL will not work to a 8.5 Application DLL and vice versa. Separate directories must be created for each version of a Gen GUI C deployment and application flows cannot occur between these different releases.