16B

Explanation
During processing of a MODESET macro, the system
found an error.
Register 15 contains a hexadecimal reason code
that explains the error: Code
Explanation
04
The macro parameter list was null.
08
The macro specified reserved bits.
0C
The macro requested an incorrect mode.
10
The macro requested an incorrect key.

System action
The system abnormally ends the program that issued
the MODESET 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 source program listing for the job.

Programmer response
Correct the macro or the program errors
that incorrectly modified the parameter list. Run the job again.

Source
Task management