Message Oracle ORA-38776 - cannot begin flashback generation - flash recovery area is disabled

ERRORcannot begin flashback generation - flash recovery area is disabled
CAUSEDuring a database mount, the RVWR process discovered that the flash recovery area was disabled. DB_RECOVERY_FILE_DEST must have been set null or removed from the INIT.ORA file while the database was unmounted.
ACTIONFlashback database requires the flash recovery area to be enabled. Either enable the flash recovery area by setting the DB_RECOVERY_FILE_DEST and DB_RECOVERY_FILE_DEST_SIZE initialization parameters, or turn off flashback database with the ALTER DATABASE FLASHBACK OFF command.

966073Oracle Flash Recovery Area/Fast Recovery Area