DFS0556I COMMAND REJECTED; DBCTL THREAD IS ACTIVE
Explanation
You entered a /STOP REGION or /STOP THREAD command for an active Database Control (DBCTL) subsystem thread. (For example, the DBCTL thread has a PSB scheduled.)
System action
The command is ignored, and the thread continues processing.
Programmer response
Determine if you specified the correct region ID, or use the ABDUMP form of the command.