Message Oracle ORA-38744 - file string is not the same file seen at start of flashback

ERRORfile string is not the same file seen at start of flashback
CAUSEA different copy of the file was accessed the last time FLASHBACK DATABASE looked at the file header. A backup of the file was restored or the meaning of the file name changed during FLASHBACK DATABASE.
ACTIONEnsure the correct file is available, then retry FLASHBACK DATABASE.