A replication job starts failing, and the following entries can be seen in the job log:
[timestamp] <01> Error Failed to save disk digests, signatureId 'scsi.0.0', location 'veeamfs:0:/scsi.0.0@c:\backup\Replicas\6560\2011-12-01T082155.vbk' at Veeam.Backup.Core.CReplicaDigestsMan.SaveAfterReplica(String signatureId, CDiskDigestsLocation diskLocation)
[timestamp] <01> Error Client error: Cannot get the value of a digests array element, because element index is out of array's range. Element index: . Array size: .
[timestamp] <01> Error Failed to process [saveDiskDigestsCli].
The storage optimizations option was changed at the Job Settings step in the job properties.
In order to fix this, you need to go to the repository where the replica metadata is stored and delete all *.vbk files. The *.vbk files will be recreated/recalculated automatically during the next run of the replication job.