What is the meaning of message XCOMM1517E FATAL ERROR IN USS, XCOMJOB TERMINATING IMMEDIATELY?
This message may arise during early XCOMJOB initialization if any of the Z/OS Unix system services called at this time fails preventing initialization to complete.
XCOMJOB will terminate after this message without further processing. The underlying problem is described in a previous XCOM1490W message, for example:
XCOMM1490W Callable service sssssss failed, RV=vvvvvvvv, RC=cccccccc, RSN=nnnnnnnn
In the message we have:
ssssssss is the name of the failing Z/OS Unix service
RV=vvvvvvvv is the return value indicating an error (usually FFFFFFFF)
RC=cccccccc is the Unix error number (errno) from the service
RSN=nnnnnnnn is the Unix reason code which provides more information
Z/OS Unix services are documented in IBM manual "UNIX System Services Programming: Assembler Callable Services Reference"
Z/OS Unix return and reason codes are documented in IBM manual "UNIX System Services Messages and Codes"