B21

Explanation
A program check interruption has occurred during
processing of the stand-alone version of the input/output configuration
program (IOCP).

Operator response
Notify the system programmer.

System programmer response
Search problem reporting databases
for a fix for the problem. If no fix exists, contact the IBM® Support Center. Provide all printed output
and output data sets related to the problem.

Source
Input/output configuration program (IOCP)