IEC503I ERROR WAS DETECTED IN AN IBM TAPE LIBRARY,dev,ser,jjj [ ,sss ]
Explanation
The CBRXLACS service returned an unsuccessful
return and reason code. This message is a multi-line write to
operator (MLWTO) and will be accompanied by other messages, inserted
as secondary lines, describing the nature of the error detected
by CBRXLACS. 
System action
Abnormally ends the task.
System programmer response
Contact the IBM® Support Center.
Source
DFSMSdfp
Module
IFG0194J
Routing code
4
Descriptor code
2,10