If any abend occurs while MFX’s STAE or ESTAE is in effect, the following message will be received:
WER999A jobname,stepname,procstepname - UNSUCCESSFUL SORT xxxx yxxxx is the abend code, and y can have the value “S” (system abend), “U” (user abend), or “W” (internally detected MFX error). The presence of the message does not necessarily mean that MFX was responsible for the error. Since STAE or ESTAE enables MFX to gain control in the event of any abend, the error may have occurred in a user program or the operating system, or in MFX itself.