If a SYSUDUMP or SYSABEND dump is produced, it should be interpreted as it would for any other program that issues a STAE or ESTAE. In particular, the ACTIVE RB chain is valid and represents the best source of the PSW and general registers at the time the error was detected.
The MFX STAE/ESTAE routine can generate a SNAP dump with ID=255 for system abends and ID=nnn for internally detected errors, where “nnn” is the internal error number in decimal. This dump will be written to SYSUDUMP, SYSABEND, SPYSET, or the message data set (whose DDNAME is generally SYSOUT), depending on which is present.
Unlike in a system dump, the PSW AT ENTRY TO SNAP is meaningless for debugging purposes. Since MFX has detected an error and forced an abend, the registers may or may not be of use. If the termination was caused by a system abend, the PSW in the appropriate RB will be accurate as in any other system abend. However, if the termination was caused deliberately by MFX, the PSW will not be useful. This will be the case if the error code in the WER999A message ends with a “W” or if the error code is a 1000-series user abend (for example, 1024 U).