REX0023S

REX0023S  hh:mm:ss.ttt User field of environment block is zero. Invalid environment.
                       Information for subtask is not available.

Explanation:

Self explanatory. This is probably caused by a storage overlay.

Issued by:

TAURIP30

System administrator response:

Obtain an SVC dump of the address space using the z/OS DUMP command and send it to Customer Care along with the job log(s).