Oracle Message ORA-01547 - warning: RECOVER succeeded but OPEN RESETLOGS would get error below

ERRORwarning: RECOVER succeeded but OPEN RESETLOGS would get error below
CAUSEMedia recovery with one of the incomplete recovery options ended without error. However, if the ALTER DATABASE OPEN RESETLOGS command were attempted now, it would fail with the specified error. The most likely cause of this error is forgetting to restore one or more datafiles from a sufficiently old backup before executing the incomplete recovery.
ACTIONRerun the incomplete media recovery using different datafile backups, a different control file, or different stop criteria.

636475Secondary Oracle error codes
1780057Corrections in BR*Tools 7.20 patch 28