Oracle Solution for Error ora-24012

ORA-24012: cannot drop QUEUE_TABLE, some queues in string have not been dropped

What triggered the Error:

queue exists in the queue table which has not been dropped. All queues need to be dropped first.

What should we do to fix it:

op all queues belonging to this queue table using the drop_queue() command. Be sure to stop the queues appropriately before dropping them. Alternately, use the force option in drop_queuetable.