Unable to Recover Immutable Files (code 2531)
A backup plan terminates with the following warning: Unable to recover immutable file(s). Consistency check detected that some immutable files are missing on backup storage and could not be recovered. View the file list below with the list of files that were not recovered.
The occurrence of this warning means that the last backup execution was done with the previous version and no Immutability was applied to log files.
This warning does not require any solution. Just continue your backup jobs.