SAS Scalable Performance Data Server 4.5 Administrator's Manual page 223

217
Commands to Nonexistent Users
the user ends the SAS session, or disconnects from a LIBNAME and the user proxy. If you
submit an OPER command to a user that is no longer in session, or to a user that has ended
a locking user proxy, you get the following message:
ERROR: Specified locking user no longer exists.
If the disconnected user used a non-locking user proxy, and you submit an OPER command,
you get the following message:
ERROR: Specified user <userID> with pid <Process-ID> no longer exists.
Either of these messages indicates that the user that was selected is no longer valid. In this
case, you must use SET USER or SET USER/RECORD to select a different user.