When using Veeam Agent for Windows (managed by the backup server), a race condition in the VSS (Volume Shadow Copy) writer might return an abnormally large timestamp or byte count, leading to an overflow in the backup job’s processing thread.

Veeam uses a guest file system catalog to enable file-level recovery from Windows or Linux VMs. If this catalog becomes corrupt—due to an unclean shutdown or disk errors—an overflow error can occur when the catalog index exceeds its expected integer limit.

If integrity errors appear, the overflow is likely database-related.

Don’t guess. Confirm overflow by reading the logs.

Look for lines like:

ERR | Overflow: Arithmetic operation resulted in an overflow.
ERR | Stack: at Veeam.Backup.Core.CHnagingBlockProcessor.ProcessBlock(Int64 offset, Int32 length)

If you see Int32 in the stack trace next to a file size or offset value, you’ve confirmed the 32-bit boundary issue.

In Veeam Backup & Replication (VBR), an “overflow error” typically manifests as:

It usually occurs when a numeric value exceeds its allocated storage limit in memory, a database column, or a data structure during backup, replication, or restore operations.