Release Information for Veeam Backup for Microsoft 365 8.1 and Cumulative Patches

Enhancements

• The mechanism of assigning licenses to processed objects was optimized to eliminate excessive request queues.
• The process of collecting information on protected users and their mailboxes was optimized to eliminate excessive queries to individual proxies within a pool.
• Multiple optimizations were made to the processing of individual objects in a proxy pool to avoid oversaturation of processing resources.
• Retention cleanup tasks were optimized to prevent them from blocking backup jobs under certain conditions.
• Processing delays and slowness in certain operations were eliminated, including retrieving session statistics and resolving objects in a proxy pool after stopping or restarting one of the proxies within a pool.

Resolved issues

• Execution of the  Get-VBOVersion fails with the error:

  The build date was not found for assembly: powershell_ise, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35.
  

Resolved Issues

• In highly loaded environments, processing operations executed on a proxy pool may take longer than expected after one of the proxies in the pool has been restarted, removed, or gone offline.

Enhancements

• Support for Ubuntu 24.04 and RedHat 9.4 as backup proxy operating systems.
• Multiple stability, performance, and scalability improvements delivered to ensure product reliability.

Resolved Issues

General

• Repository indexing may fail with the error:

  Retry transient error after 00:00:00: Npgsql.NpgsqlException (0x80004005): Exception while reading from stream.
  

• Protection of a host running Veeam Backup for Microsoft 365 using other Veeam solutions may fail with the error:

  VSSControl: Failed to prepare guest for freeze, wait timeout {value} sec.
  

• Under certain conditions, retention cleanup may fail to start, displaying the error:

  Cannot start the retention session because this repository is in use by other sessions.
  

• On immutable object storage repositories associated with a proxy  pool, the extension of the immutability period may fail with the error:

  Item previews are missing (ID: {ID} ({value} bytes)).
  

Upgrade 

• Upgrading a Linux proxy in a proxy pool may fail with the error:

  The command timed out: sudo systemctl stop Veeam.Archiver.Proxy. Current output: {proxy name} was not upgraded.
  

• Under certain conditions, indexing and upgrading an object storage repository may get stuck.
• Upgrading an object storage repository may get stuck.
• Under certain conditions, upgrading an object storage repository may fail with the error:

  Cannot find a web backup for the internal web ID: {ID}.
  

Backup and Backup Copy

• A backup or backup copy job with SharePoint, OneDrive, or Teams data may fail with the error:

  Cannot find object {path}.
  

  For more details, see KB4678.
• Under certain conditions, an Exchange backup job processed in a proxy pool may remain stuck in a running state.
• Under certain conditions, a backup job processed in a proxy pool may become stuck in a running or failed state, and attempts to stop or restart the job fail with errors.
• An Exchange backup job may fail with the error:

  Processing mailbox {user@domain.com} failed with error: Unable to access object storage (reason: Cannot access a disposed object. Object name: 'Veeam.Core.Memory.Reference`2.
  

• A OneDrive backup job may mistakenly attempt to download items blocked by a virus scanner, resulting in a failure with the warning: Failed to backup item:

  {path}, Failed to download block in time: {time}.
  

• The size of backup data transferred by a backup copy job can significantly exceed the size of the source data.
• An Exchange backup to an object storage repository may fail with the error:

  Npgsql.PostgresException (0x80004005): 23505: duplicate key value violates unique constraint “pk_exchange_items_previews_uploads”.
  

• Under certain conditions, a backup copy job transferring SharePoint and Teams data may get stuck in the running state.
• Under certain rare conditions, a backup copy job transferring Exchange data to an archive-tier object storage repository fails with the error:

  The response status code does not indicate success: 409 (this operation is not permitted on an archived blob).
  

Restore

• In Veeam Explorer for Microsoft SharePoint, browsing a SharePoint, Teams (files), or OneDrive backup from an object storage repository may fail with the error:

  Cannot find object {path} or Task failed with exception (task ID: {ID}).
  

  For more details, see KB4678.
• Restoring of Exchange data may fail with the error:

  Failed to get task result because the task does not exist (ID: {ID}).
  

• Under certain rare conditions, when exploring SharePoint backups stored in a Jet-based repository, some items may not be displayed. For more details, see KB4704.
• When initiated via REST APIs, exploring a SharePoint backup containing a Discussion Board may fail with the error:

  Object reference not set to an instance of an object.
  

• In Veeam Explorer for Microsoft Exchange, when an email item is exported to a .MSG file, diacritics are replaced with fallback characters.
• Veeam Explorer for Microsoft SharePoint may not display any content if the backup was retrieved from an archive-tier object storage.

REST APIs

• Execution of the following endpoint with the useAuthentication parameter set to false may fail with the error below:
  (POST) /v8/RestoreSessions/{restoreSessionId}/organization/mailboxes/{mailboxId}/items/sendToDifferentAddress

  Object reference not set to an instance of an object.