ORA-19731: cannot apply change to unverified plugged-in datafile [string]
Cause: Recovery was not able to verify the referred datafile according to information in the control file. Before encountering this change vector for this file, somehow recovery did not encounter the file conversion redo that is supposed to verify the file. This may happen due to corrupted or incorrect control file used for media recovery.
Action: Use the correct control file and continue recovery.