After an upgrade of the Automation Engine from an older version to version 11.1, 11.2, 12.0 or 12.1, the z/OS CallAPI fails. This may happen even though the CallAPI was updated as well.
The z/OS CallAPI doesn’t encrypt messages with the encryption algorithm which is expected by the CP. So they are rejected by the CP:
U00003354 Unencrypted message of '&01' is not permitted.
The CallAPI output doesn’t show the cause, it just gets condition code 12:
IEF142I CALLA112 UCCALL - STEP WAS EXECUTED - COND CODE 0012
And the following message in the CallAPI log is issued:
U03000000 Program 'UC4 Call Interface', version '12.0.0+build.3427', change list '7854944' started.
U00003413 Socket call '0' returned error code '0'.
U03000002 Program 'UC4 Call Interface' version '12.0.0+build.3427' ended abnormally.
Sometimes the message shows a different error code:
U00003413 Socket call '0' returned error code '1'.