202

Explanation
During processing of a POST macro, the system found
an error with an event control block (ECB).
Register 15 contains
a hexadecimal reason code that explains the error: Code
Explanation
00
The system found an incorrect address for a request block (RB)
in the 3 low-order bytes of the ECB specified by the problem program. The
system places the address of the RB in the ECB during processing of
a WAIT macro.  This address must remain in the ECB until a POST macro
places a post code or zeros in the ECB.

04
The waiting RB is not enabled for interrupts.
08
For a POST in a problem program protection key and a WAIT in a
system protection key, the ECB to be posted does not match any ECB
being waited on.
0C
For a WAIT in a problem program protection key, the ECB address
is incorrect. This can also mean that the program issuing the
WAIT has specified a list of ECBs and one of those ECBs is not valid.
This could happen if the ECB storage has been released by another
process.

System action
The system abnormally ends the program that issued
the POST macro.

System programmer response
  If the error recurs and the program
is not in error, look at the messages in the job log for more information.
Search problem reporting data bases for a fix for the problem. If
no fix exists, contact the IBM® Support
Center. Provide the program listing and the assembly listing associated
with the job.

Programmer response
Ensure that the contents of the ECB were
not modified after the WAIT macro and before the POST macro. Correct
the error.  Run the job again.

Source
Task management