ORA-38897
cannot remove DB_FLASHBACK_LOG_DEST in INIT.ORA file after flashback database has been enabled with it
Cause
Flashback logs can only be in either DB_RECOVERY_FILE_DEST or DB_FLASHBACK_LOG_DEST but not both. Because flashback database is already enabled with flashback logs in DB_FLASHBACK_LOG_DEST, one cannot remove DB_FLASHBACK_LOG_DEST in the INIT.ORA file.
Action
Add back DB_FLASHBACK_LOG_DEST in the INIT.ORA file or remove it before turning on flashback database.