Any z/OS (platform MVS, SW OS/390) users getting this same error??? I am. I'm actually testing v11.2 load lib and binary files with v12.1 AE.
This is the same files we're using in our 11.2 AE and it works (i.e. the CALLAPI).
Error MSG:
U03000000 Program 'UC4 Call Interface', version '11.2.2+build.622', change list '7627775' started..
U00003413 Socket call '0' returned error code '0'..................................................................
U03000002 Program 'UC4 Call Interface' version '11.2.2+build.622' ended abnormal..............................
I found the solution ---
z/OS CallAPI Interface fails after Automation Engi - CA Knowledge