CASKC0213E Transaction trans-id abend AKCC. Purge threshold of its TRANCLASS has been reached. Backout successful.

Transaction trans-id has been purged due to TRANCLASS PURGETHRESH constraints.
System Action:
The transaction is abended and the transaction dump has been suppressed.
Resubmit the transaction. The cause of the abend may be a temporary stress condition in the system. If the problem persists, determine why the TRANCLASS purge threshold has been reached. Ensure that PURGETHRESH has been specified correctly. Also, ensure that the MAXACTIVE value of the TRANCLASS has not been set too low. Transactions attached after the MAXACTIVE limit has been reached are immediately queued subject to the PURGETHRESH limit. If PURGETHRESH and MAXACTIVE are set correctly, look for a more general problem which has caused a decrease in the capacity of the system to execute transactions in the TRANCLASS. The decrease might, for example, be caused by a connected CICS region which processes requests for transactions in the TRANCLASS, if this connected region has slowed down.
Terminal end user & CSMT