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

Enhancements

• Optimized memory usage for REST API requests related to Exchange data restoration.
• Improve generation time for the Mailbox Protection and User Protection reports by reading data from the database instead of the repositories.
• Optimized memory usage for backup proxy service.
• Retries are implemented to address the 'Failed to open mailbox' error that can affect bulk Exchange mailbox restores. 
• The restore session action log now shows a failure reason if an item restore fails.
• The public IP address SKU type is updated to Standard in the VM configuration for the Azure archiver appliance.
  For more details, see KB4727. 
• Enhanced logic for concurrent processing of newly created jobs and incremental job runs on a single backup proxy or proxy pool.
• Improved logic of sending resolved objects to processing on a proxy pool.

Resolved Issues

General

• An object storage repository associated with a proxy pool may become invalid with the following error in logs:

  Repository is in an invalid state. The local cache and object storage are not synchronized.
  

• Collecting session logs for a backup job running on a proxy pool fails with the error:

  Could not find a part of the path {path}.
  

• Removing an M365 organization from Veeam Backup for Microsoft 365 may fail with the error:

  null value in column "organization_id" of relation "organization_webs" violates not-null constraint.
  

• A backup repository may get stuck in the Indexing state after its owner (a proxy or a proxy pool) has been changed.
• No email notification is sent when a backup job fails, even if the 'Notify on failure' option is enabled.
• Retention applied to an object storage repository containing SharePoint or OneDrive data fails with the error:

  Cannot find a blob containing the file (file ID: {ID}, file version: {version}).
  

Backup and backup copy

• A backup job containing SharePoint or OneDrive data and targeted to an object storage repository appears stuck in the UI with the following recurring lines in logs:

  • Resource is found in cache (memory cache: { value }, cache size: { value }, key: {value}, resource size: {value })
    

  • Listing bucket objects (Bucket: {value})...
    

• A backup copy job transferring SharePoint or OneDrive data to an object storage repository fails with the error:

  Cannot find versioned blob: {path}.
  

• Backup of SharePoint or OneDrive data to an immutable object storage repository fails with the error:

  Failed to process site: {URL}. Cannot apply immutability because blob {value} does not have a version yet.
  

• Under certain conditions, the backup of a Discovery Search Mailbox fails with the error:

  Unable to cast object of type 'System.Collections .Generic.List`1[System.String]' to type 'System.Management.Automation.PSObject'.
  

• Exchange backup fails with the error:

  Exception of type 'System.Exception' was thrown.
  

• Exchange mailbox backup may fail with the error:

  Error in deserializing body of reply message for operation 'SyncFolderItems'. There is an error in XML document ({0}, {1}).
  

• Exchange mailbox backup may fail with the error:

  The HTTP service located at https://outlook.office365.com/EWS/Exchange.asmx is unavailable. This could be because the service is too busy or because no endpoint was found listening at the specified address. Please ensure that the address is correct and try accessing the service again later.
  

• If an initial mailbox backup to object storage is interrupted and the repository's cache is rebuilt, subsequent backups will fail with the error:

  Mailbox does not exist: {ID}.
  

• If a site list includes an item with an attachment containing the “#” character in its name, the SharePoint backup completes with the warning:

  Failed to backup list: {name}. File Not Found
  

• An Exchange group mailbox backup may stall with no data processed, showing recurring log events:

  Syncing folder items: Team Chat...
  

• Due to an expired page token, a backup job processing Teams data fails with the error:

  The response status code does not indicate success: 400 (Bad Request)
  

• Backup of SharePoint, OneDrive, and Teams files data may fail with the ‘Failed to download block in time’ error if any of the following errors occur during the processing:

  • The remote server returned an error: (400) Bad Request.
    

  • The response status code does not indicate success: 404 (Not Found).
    

  • The response status code does not indicate success: 403 (Forbidden).
    

  • Response status code does not indicate success: 409 (This operation is not permitted on an archived blob.)
    

  • The remote server returned an error: (412) PRECONDITION FAILED.
    

• Under certain conditions, a backup copy job transferring SharePoint data may seem to be stalled.
• Under certain conditions, a backup copy job transferring SharePoint data fails with the error:

  Unable to read beyond the end of the stream.
  

• A backup copy job transferring Exchange data, may initiate numerous excessive requests for downloading a list of change keys for processed mailboxes.
• A backup job running on a proxy pool may fail with the error:

  Object unexpectedly changed the proxy.
  

REST API

• Executing the (GET) v8/VexEmailSettings request may fail with the error:

  Exception of type 'System.Exception' was thrown.
  

• SharePoint folders are not returned when running the (GET) v8/RestoreSessions/{restoreSessionId }/Organization/Sites/{siteId}/Documents request with the includeFolders parameter set to True.
• A Teams restore session opened via the (POST) v8/Jobs/{jobId}/explore endpoint may remain open after one hour of inactivity.
• When restoring SharePoint data using REST APIs, the latest version of each restored item gets duplicated in the target location.
• The content of an email message containing Greek or Chinese characters are not visible after being saved from the backup to a .msg file using the (POST) v8/RestoreSessions/{restoreSessionId}/organization/mailboxes/{mailboxId}/items/{itemId}/save request.
• A new restore session created via the (POST) v8/Organizations/{organizationId}/explore endpoint may become unresponsive if the preceding restore session was forcibly closed during the execution of the (GET) v8/RestoreSessions/{restoreSessionId}/Organization/Sites/{siteId}/Items request.

PowerShell

• Data move from a Jet-based Repository to an Object Storage Repository using the script provided in the KB3067 may fail with the error:

  Exception of type 'System.OutOfMemoryException' was thrown.
  

• If the organization has been deleted from Veeam Backup for Microsoft 365, using the Remove-VBOEntityData cmdlet to delete backup data from a repository fails with the error:

  Organization does not exist: ID {value }
  

Restore

• In a BaaS scenario, Veeam Explorer for Microsoft Teams is not displaying the “Veeam Backup for Microsoft 365 service provider” option to allow tenants to connect to their service provider.
• In a BaaS scenario, Veeam Explorer for OneDrive and Veeam Explorer for SharePoint attempting to connect to a service provider using a self-signed certificate fail with the error:

  Cannot find resource named 'UnderlineConverter'. Resource names are case sensitive.
  

• If a mailbox folder has been excluded from backup via the Folder setting in General Options and then later included again, the content of that mailbox folder may not be displayed when browsing a backup.
• When a previously backed-up user account is deleted from an M365 tenant and subsequently re-created with the identical username, restore data for this user via the Restore Portal fails with the error:

  Enumerator failed to MoveNextAsync.
  

• Exploring backups in Veeam Explorer for Microsoft Exchange may fail with the error:
  

  No data is available for encoding 1252. For information on defining a custom encoding, see the documentation for the Encoding.RegisterProvider method.
  

• Under certain conditions, Teams file restore, may fail with the error:

  Object reference not set to an instance of an object.
  

• Under certain conditions, opening an Exchange restore point may fail with the warning ‘Some backup data is not available. This can occur if some of the backup proxies or repositories are not accessible’ and the error in product logs:

  duplicate key value violates unique constraint "pk_folders_history"
  

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.