oracle error - ORA-00223: convert file is invalid or incorrect version

ORA-00223:

convert file is invalid or incorrect version
Cause: An Oracle7 to Oracle8 convert file contains invalid data or was created with an different version of the migration utility. This error can also be caused by incorrect ORACLE_HOME environment variable when ALTER DATABASE CONVERT command is issued.
Action: Use a correct version of the convert file or regenerate it with the migration utility. Make sure that the migration utility is the same version as the Oracle8 RDBMS executable and that the ORACLE_HOME environment variable is properly set.

oracle error - ORA-00222: operation would reuse name of a currently mounted control file

ORA-00222:

operation would reuse name of a currently mounted control file
Cause: The filename supplied as a parameter to the ALTER DATABASE BACKUP CONTROLFILE command or to cfileSetSnapshotName matches the name of the specified currently mounted control file.
Action: Retry the operation with a different filename.

oracle error - ORA-00221: error on write to control file

ORA-00221:

error on write to control file
Cause: An error occurred when writing to one or more of the control files.
Action: See accompanying messages.