0B5

Explanation
The master subsystem was unable to attach the converter. It
is possible there is conflict between a TSO/E logon procedure and
a subsystem name.

System action
The system does not start the requested subsystem.

System programmer response
Check for any conflicts between
TSO/E logon procedures and active subsystem names. If so, resolve
the conflict. In particular, look for message IKJ601I which contains
the name of the logon procedure in use when TSO/E terminated abnormally. Search
problem reporting data bases for a fix for the problem. If no fix
exists, contact the IBM® Support
Center.

Source
Initiator/terminator