Improper configuration of the Destination Port field when creating an application mapping.
The "Destination Port" field should be different then the original port and it should be a port number ideally over 65000 so that it is not in use by another application.
To resolve this follow the steps below on 9.5.0 and earlier:
1. Go into the Admin->Application Definitions page and delete the Application Definition that caused the problem.
2. On the Console server open a command prompt and run:
delete from protocol_domains where description not in(select description from application_mappings);
3. Recreate the Application Definition with a destination port over 65000 that is not currently in use by any other application like below: