ORA-38739: Flashback log file is more recent than control file.
Cause: The control file change sequence number in the flashback database log file was greater than the number in the control file. This implies that the wrong control file was being used. Note that repeatedly causing this error can make it stop happening without correcting the real problem. Every attempt to open the database will advance the control file change sequence number until it is great enough.
Action: FLASHBACK DATABASE can only be used with the current control file. If it is not available, then a restore and an incomplete recovery must be performed instead.