OCI-19749
Flashback failed because file# string metadata is unknown to current control file
Cause
The file creation system change number (SCN) is less than the restore point SCN and there is no record of the file on the current control file, causing flashback to the restore point to fail.
Action
If flashing back to the restore point is still required, then the database should switch to an incarnation that has the complete information required for flashing back to the restore point.