Oracle Message ORA-07264 - spwat: semop error, unable to decrement semaphore.

ERRORspwat: semop error, unable to decrement semaphore.
CAUSESemop system call returned an error. Semaphore set may not exist.
ACTIONCheck errno. Semaphore ID is returned in sercose[0]. Verify semaphore set exists. A possible cause for this error is that a shutdown abort was done while this process was running.