Message Oracle ORA-38746 - error occurred while restoring data block (file# string, block# string)

ERRORerror occurred while restoring data block (file# string, block# string)
CAUSEAn error occurred during a FLASHBACK DATABASE command. See other errors on error stack.
ACTIONInvestigate why the error occurred. It may be that the flashback database log data is corrupt. If so, a restore and an incomplete recovery must be performed instead.