77D

Explanation
During processing of an EVENTS macro, the system
found an error in the macro input parameters.
Register 15 contains
a hexadecimal reason code that explains the error: Code
Explanation
04
A caller issued an incompatible level of the EVENTS macro.
08
Both WAIT=YES and WAIT=NO were specified.

System action
The system abnormally ends the program that issued
the EVENTS 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 assembly listing for the job.

Programmer response
Verify the EVENTS macro input parameters,
the level of the macro, and the contents of register 0. Correct the
error.  Run the job again.

Source
Task management