Oracle Error Message
RMAN-06159: error while looking up backup set
Reason for the Error
An error occurred while looking up the specified backup set in the recovery catalog or target database control file.
Solution
This error is accompanied by other errors describing the reason for the failure. Ensure that the key is entered correctly. If the backup set was created when the recovery catalog was not available, then a RESYNC CATALOG must be done to update the recovery catalog.