Writer Name: Backup Exec Deduplication Storage, Writer ID: {55F6D76D-8617-4FC8-81E9-DF0DE529B555}, Last error: The VSS Writer timed out (0x800423f2), State: Failed during thaw operation (10).
High Disk I/O triggered by Content Router Queue Processing (CRQP) causes VSS to delete the snapshot created for backup.
Workaround: Move the backup of the deduplication storage folder into its own seperate job to be executed after queue processing has completed.
If queue processing spans to the following day, please see related issue https://www.veritas.com/docs/000020404