DFS3609 EXTERNAL SUBSYSTEM TASK ABENDING/ABENDED. COMMAND REJECTED.

Explanation
 The IMS external subsystem task terminated
abnormally or was in the process of terminating when the /START
SUBSYS command was entered.

System action
 The command is rejected. IMS continues
processing.

Operator response
 Notify the system programmer.

System programmer response
Enter the /START SUBSYS command
as soon as the termination has completed to restart the connection.