0x00150015 (1376277) The System Log Stream (SLS) interface lost session tracking for a log stream.

Explanation
Session tracking for a z/OS system log stream no longer exists.

This kind of condition can be reported during clean-up processing because of a 
prior error or inactivity.

User response

Check the diagnostic log for previous errors that might have been reported while the SLS interface was 
trying to access a system log stream. If there are indications of prior issues, resolve those first, 
then retry the operation. If this error persists, contact IBM Technical Support. 