Oracle Error Message
ORA-07264: spwat: semop error, unable to decrement semaphore.
Reason for the Error
Semop system call returned an error. Semaphore set may not exist.
Solution
Check 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.