GOS006I   SOM/MVS SUBSYSTEM JOBNAME jobname IS NOT VALID.

Explanation

The SOMobjects® procedure name, which is used as the name of the subsystem, is not a valid 1-4 character name.

In the message text:
jobname
The name of the SOMobjects job or started procedure.

System action

The SOMobjects address space ends.

System programmer response

Ensure that the SOMobjects job name/procedure name is a valid subsystem name (1-4 characters).

Source

SOM