...
BugZero found this defect 263 days ago.
Starting around January 19th, 2024, Exchange backup within Veeam Backup for Microsoft 365 may fail with the following error: Invalid serialized stream, unknown opcode found: 4
Veeam has observed that there have been changes to the Serialized Property for Exchange items.
The issue was fixed starting in: Veeam Backup for Microsoft 365 7 - Cumulative Patch 7.0.0.4901 (P20240123) Veeam Backup for Microsoft 365 7a - Cumulative Patch 7.1.0.1501 (P20240123)