Oracle® Database 11g / 12c / 18c error codes ORA-01252: cannot prevent writes - file [string] in recovery manager backup

ORA-01252: cannot prevent writes - file [string] in recovery manager backup

Oracle Error Code: ORA-01252

Cause: An attempt to make a tablespace read only or offline normal found that a recovery manager proxy backup is in progress. If the file is made offline or read-only, then the file header cannot be updated when the backup is complete.

Action: Wait for the Recovery Manager backup to complete and retry this command.