Message Oracle RMAN-08118 - WARNING: could not delete the following archived redo log

ERRORWARNING: could not delete the following archived redo log
CAUSEThe routine deleteArchivedLog() could not delete an archived redo log on the target instance.
ACTIONCheck the accompanying file specification and the associated error messages. The file specification indicates what archived redo log on the target instance RMAN was trying to delete and the error messages indicate why RMAN was unable to delete it. Resolve the problem by first confirming that the archived redo log in question has been backed up, do the deletion manually, and then do a crosscheck so that RMAN is aware of the deletion.