MSMMUFS abends with a S0C4 during startup, if startup option BREAK is coded. A PTF is not available Datacom/AD 14.0. This is not related to z/OS 2.5.
BREAK being coded in CUSMAC(MUFSTART).
MUF abends with a S0C4 and interrupt code 04 in module DBDVCPR at or around
Release : 6.0
Component : Chorus Software Manager
In your CUSMAC(MUFSTART) member that is assigned to SYSIN DD in the MSMMUFS startup comment out this line:
BREAK 50 ALLOW INTERRUPT
Start the MSMMUFS.
This is a circumvention recommended by the Datacom/AD 15.0 LU01953 PTF.