051

Explanation
Alternate CPU recovery (ACR) encountered an unrecoverable
error while recovery was in progress for another processor. ACR attempted
to recover but was unsuccessful. This is probably a software error.

System action
The system: Issues message IEA857W
Tries to write a logrec error record for the failed processor
Places all processors in a wait state X'051'

Operator response
If requested by the system programmer, obtain
a stand-alone dump. ReIPL the system.

System programmer response
Look at accompanying message IEA857W
to identify the error. If a search of the program reporting databases
shows no existing fix, report the problem to the IBM® Support Center. Provide the stand-alone dump
the logrec error records.

Source
Alternate CPU recovery (ACR)