ORA-00205 error in identifying controlfile, check alert log for more info

Cause: The system could not find a control file of the specified name and size.

Action: One of the following:

Check that the proper control file name is referenced in the CONTROL_FILES initialization parameter in the initialization parameter file and try again.

When using mirrored control files, that is, more than one control file is referenced in the initialization parameter file, remove the control file name listed in the message from the initialization parameter file and restart the instance. If the message does not recur, remove the problem control file from the initialization parameter file and create another copy of the control file with a new file name in the initialization parameter file.