Oracle® Database 11g / 12c / 18c error codes ORA-01546: tablespace contains active rollback segment '[string]'

ORA-01546: tablespace contains active rollback segment '[string]'

Oracle Error Code: ORA-01546

Cause: Tried to make a tablespace that contains active rollback segment(s) offline or read only

Action: Shutdown instances that use the active rollback segments in the tablespace and then make the tablespace offline or read only