The task has been purged, probably due to operator action such as a CEMT TASK PURGE command. The task might also have been purged as a result of CICS issuing a purge request.
The transaction is abnormally terminated with a transaction dump.
Use the transaction dump to determine why the task was purged. In particular, if the purge was operator initiated, the dump should be useful in determining why this task needed to be explicitly purged.