The delete failed due to a problem with the AT schedule file.
Any action to correct the problem should be performed on that computer. LAN Manager cannot find the job you are trying to delete.
Check the job identification number by typing AT. Try again to delete the job, using the correct job identification number. If the error persists, the schedule file, SCHED.LOG, may be damaged. Restore SCHED.LOG from a backup copy, or delete it and create a new one with the AT utility. SCHED.LOG is in the LANMAN\\LOGS directory.