Oracle® Database 11g / 12c / 18c error codes ORA-00706: error changing format of file [string]

ORA-00706: error changing format of file [string]

Oracle Error Code: ORA-00706

Cause: An attempt to change the block0 format of the specified file failed because the file is read-only or offline.

Action: Make the file read-write or bring the file online and set the BLK0_FMTCHG event.