Oracle® Database 11g / 12c / 18c error codes ORA-01147: SYSTEM tablespace file [string] is offline
ORA-01147: SYSTEM tablespace file [string] is offline
Oracle Error Code: ORA-01147
Cause: A file belonging to the SYSTEM tablespace has been marked offline by the DBA. The database cannot be started until all SYSTEM tablespace files are online and openable.