Message Oracle TNS-01159 - Internal connection limit has been reached; listener has shut down

ERRORInternal connection limit has been reached; listener has shut down
CAUSEThe internal Oracle Net connection list is full. The listener is configured to use too many Oracle Net connections.
ACTIONReduce the number of listen addresses or services connected to the listener. For further details, turn on tracing and reexecute the operation. If error persists, contact Oracle Customer Support.