VM Loses Connection During Snapshot Removal

Challenge During the snapshot removal step of a Veeam Backup & Replication task, the source vSphere VM loses connectivity temporarily. Cause Veeam does not remove the snapshot itself; Veeam sends an API call to the vSphere environment to have the action performed. The snapshot removal process...

The "Index was outside the bounds of the array" error while opening nworks UI

When the error "Index was outside the bounds of the array" occurs when opening nworks UI, this article provides the steps to address the corrupted XML file...

SureBackup Ping Test Timed Out

Challenge A VM or group of VMs fail to pass the SureBackup Ping Test. Solution Below is a list of the most commonly observed causes of Ping Test failures and solutions for each. A router exists between the Veeam Server and Virtual Lab. The vNIC for the Isolated Network is misconfigured. The...

How to Manually Update GPG key on Veeam Appliances

Article Applicability This article is specifically regarding the Veeam Appliances used in conjunction with Veeam Backup & Replication 13. Including the Veeam Software Appliance, Veeam Infrastructure Appliance, and Veeam Hardened Repository deployed from the Veeam Infrastructure Appliance. For...

"Failed to connect to the database." Updater Configuration Check

Challenge When updating Veeam Backup & Replication the Configuration Check fails with either: Failed to connect to PostgreSQL server localhost:5432. An existing connection was forcibly closed by the remote host SSPI authentication failed for user Cause The account being used to run the update...

Backup Copy or Replication job using WAN accelerators fails with "Source WAN accelerator error: Failed to decompress LZ4 block"

Challenge A Backup Copy or Replication job that uses WAN accelerator fails with any of the following errors: Error: Source WAN accelerator error: Failed to decompress LZ4 block: Bad crc Error: Source WAN accelerator error: Failed to decompress LZ4 block: Incorrect decompression result or length...

WAN Accelerator Fails to Install

Challenge When creating a new WAN Accelerator or reconfiguring an existing WAN Accelerator, the installation of the WAN Accelerator package fails with the error: Error Installing package WAN Accelerator Error: Error 1920.Service Veeam WAN Accelerator Service VeeamWANSvc failed to start. Verify...

Unexpected Increase in Exchange Incremental Data Processed By Veeam Backup for Microsoft 365

May 2025 Update This article has been updated with new information regarding the February 2025 occurrence and the results of the subsequent investigation. Issue Summary First Occurrence -- August 7 - August 21, 2023 Some customers using Veeam Backup for Microsoft 365 to back up Microsoft 365...

Veeam Backup & Replication 9.0 Day 0 Update

Challenge This update is provided to enable upgrading existing installations of Veeam Backup & Replication 9.0 partner preview build 9.0.0.773 to generally available version of Veeam Backup & Replication 9.0 build 9.0.0.902. This update addresses a number of issues reported by our partners on the...

0x8004230F or Error: VSSControl: -2147212529 (VSS_E_UNEXPECTED_PROVIDER_ERROR)

Challenge A job fails with the error: Failed to prepare guest for hot backup. Error: VSSControl: -2147212529 Backup job failed. Discovery phase failed. Cannot add volumes to the snapshot set. Cannot add a volume to the snapshot set. Volume name: \?\Volume. Cannot add volume to the set of volumes...

CVE-2025-23120

Veeam Software Security Commitment Veeam® is committed to ensuring its products protect customers from potential risks. As part of that commitment, we operate a Vulnerability Disclosure Program VDP for all Veeam products and perform extensive internal code audits. When a vulnerability is...

After Enabling MFA, Veeam Backup Server Is Listed as Inaccessible in Veeam Service Provider Console

Challenge After enabling multi-factor authentication MFA in Veeam Backup & Replication or Veeam Cloud Connect, that server may become listed as "inaccessible" within Veeam Service Provider Console yet the Veeam Management Agent for VSPC continues to display a "healthy" status. Cause When MFA is...

How to Activate Access to Microsoft Graph Teams Export APIs

Preliminary Action This article documents how to configure your app registration to access the Microsoft Graph Export API for Teams, which is necessary to enable Veeam Backup for Microsoft 365 6a and newer to protect Teams public channel posts. Once the Teams Protected APIs are accessible and Vee...

Repository 'Used Space' Value Greater Than 'Capacity'

Challenge A Repository listed under Backup Infrastructure Backup Repositories has a 'Used Space' value that is greater than the 'Capacity' of the storage. Cause This occurs when repositories are backed by storage that has the ability to reduce the space used by restore points, like deduplication...

Using the Diskshadow Utility to Manually Test VSS Operations

Windows Server Required This article documents how to use Diskshadow , which is only available in Server versions of Windows 2008+. Purpose This article documents how to manually create a volume shadow copy using the Diskshadow command-line utility in Windows. Cause Veeam products use the Microso...

An error message "Collecting thread has failed to initialize (Time difference between Veeam Monitor server and ESX host is too large. Make sure that NTP is enabled on ESX host and try again.) and will be stopped" in Veeam Monitor

Challenge The error "Connection problems" appears with vCenter server or ESXi host in Veeam ONE Monitor client infrastructure view. vCenter server or the ESXi host becomes grayed out: No data goes to the Veeam ONE Monitor client and into the Veeam ONE database. vCenter server or ESXi might be...

Applying Custom Settings to Veeam Software Appliance

Purpose This article documents the configuration files on the Veeam Software Appliance that correspond to registry locations in Windows used for custom settings in Veeam Backup & Replication. Custom registry-based settings for Veeam Backup & Replication on Windows can also be applied to the Veeam...

How to Configure PXE Booting of Veeam Agent for Linux Recovery Media

Veeam Agent for Linux Version Requirement Starting with Veeam Agent for Linux 6.1.2, the Veeam Recovery Media is designed to be capable of use in PXE booting.veeam-recovery iso released after 22-May-2024 Purpose This article documents how to configure Linux to PXE boot the Veeam Agent for Linux...

Vulnerability Scanner Detection Related to CVE-2023-38545

Veeam Backup & Replication 12.1.2 Release - Article Update With the release of Veeam Backup & Replication 12.1.2, the VDDK libraries, which contained the libcurl library, are no longer included with the Veeam Transport package. After upgrading, the Veeam Transport Package on remote components wil...

Support Statement regarding Microsoft CVE-2023-24932

Challenge Microsoft recently released update KB5025885 containing changes to secure boot. These changes require specific actions to be taken to continue using Veeam Agent for Microsoft Windows bare metal recovery media and other restore operations. After applying the Microsoft Update with...

Antivirus Exclusions for Veeam Backup for Microsoft 365

Purpose This article documents antivirus exclusions that may be created to reduce the impact that antivirus software has on the functionality of Veeam Backup for Microsoft 365. These antivirus exclusions may be applied to the Windows built-in antivirus or third-party antivirus software. Note:...

Veeam Recovery Media creating fails with "This access control list is not in canonical form and therefore cannot be modified" error

Challenge During a Veeam Agent for Microsoft Windows backup job the following warning occurs: Collecting recovery media files Details: This access control list is not in canonical form and therefore cannot be modified. Copy The warning may appear in the following cases: Veeam Recovery Media is...

Task fails with error: Application is Shutting Down

Challenge Jobs of any type fail with the error, "Application is shutting down." For example: Application is shutting down. Failed to download disk. Shared memory connection was closed. Failed to upload disk. Agent failed to process method DataTransfer.SyncDisk Copy BackupSynthesizedStorageToTape...

Tape Jobs fail with I/O errors or (SCSI) Bus resets

Challenge Failures occur during the File to tape or Backup to tape jobs. The jobname.log shows error messages similar to: error: The request could not be performed because of an I/O device error error: Tape fatal error.\nThe I/O bus was reset Cause Depending on the type of connection, controller ...

How to Create a Veeam Support Case

Phone Support To improve case handling, you must Open a Case via the portal before calling in. The phone system will ask for your case number and use advanced routing to connect you with the engineer handling your case or an appropriate product/feature specialized support engineer. Purpose This...

Migration to Unified Veeam Data Cloud FAQ

Below are the most commonly asked questions. What changed with the Veeam Data Cloud for Microsoft 365 experience? Veeam transitioned customers to the Veeam Data Cloud Platform, a unified multi-workload interface. This new experience allows customers to manage Microsoft 365, Entra ID, Salesforce,...

Immutability Warning for Data Domain Repository: "Immutability flag on backups was set with warning"

Challenge A backup job that targets a Dell Data Domain repository completes with the warning, "Immutability flag on backups was set with warning: ", specifically with the endings: Immutability period for some backups exceeds the maximum value allowed by the target repository, using the maximum...

exFAT Filesystem May Corrupt Veeam Backup Files

Challenge Testing performed in Veeam labs has determined that, in rare cases, Veeam backups may become corrupted when stored on the exFAT file system. Cause The issue appears to be related to a buffer management issue in the exFAT file system driver. There are no similar issues on other, more...

Release Information for Everpure FlashArray Plug-In for Veeam Backup & Replication

This plug-in leverages the Veeam Universal Storage API, which enables storage OEMs to allow Veeam Backup & Replication integration to the arrays for backup and replication jobs. Requirements Before installing Everpure FlashArray Plug-In v2.2.331, ensure that you are running Veeam Backup &...

How to Change Veeam ONE Web Client Port

Purpose This article documents the procedure for changing the port used by the Veeam ONE Web Client, which by default is 1239. Solution Desktop Shortcut Not Automatically Updated This procedure does not update the Veeam ONE Web Client shortcut on the desktop C:\Users\Public\Desktop. Part 1: Updat...

Zlib decompression error: [-3] | Failed to decompress LZ4 block

Challenge A Backup Job or Restore fails with either of the following errors: Zlib decompression error: -3. or Failed to decompress LZ4 block: Cause When the software reads from a an existing restore point it performs error detection using Cyclic Redundancy Checks CRC to validate the data. The err...

How to Configure HTTP Proxy for Linux-based Veeam Components

Purpose This article documents how to configure HTTP and HTTPS Proxy settings for Linux-based components, including the Veeam Software Appliance and JeOS-deployed Veeam Infrastructure Appliances, in environments that require a proxy to access the internet. Note: For proxy configuration settings f...

Release Information for Veeam Backup & Replication 12 Day 0 Update

Update Applicability This "Day 0" update for Veeam Backup & Replication 12 is strictly intended for servers using the RTM release build 12.0.0.14 02. If Veeam Backup & Replication 12 GA build 12.0.0.14 20 is installed, this update can be ignored as it is not needed. All resolved issues listed in...

Build Numbers and Versions of Veeam Plug-In for Nutanix AHV

This KB article lists all versions of the Veeam Plug-In for Nutanix AHV and their respective appliance build numbers. Version | Plug-In Build | Appliance Build | Release Date | Release Notes ---|---|---|---|--- Veeam Plug-In for Nutanix AHV 10 Releases Veeam Plug-In for Nutanix AHV 10.0 Included...

How to Migrate Veeam Service Provider Console to a New Server

The article describes how to move Veeam Availability Console installation and its database to a new server...

How to Migrate the Veeam ONE Database

Article Applicability This article is specifically about relocating the Veeam ONE database to a different Microsoft SQL Server Instance and the Veeam ONE deployment remaining on the same machine. For information about relocating the Veeam ONE deployment, review: KB1801: How to Migrate Veeam ONE...

How to Start a SureBackup Job in Troubleshooting Mode

Purpose This article documents how to start an individual VM that has failed SureBackup validation in "Troubleshooting mode." Solution Troubleshooting Mode causes the selected VM in the SureBackup job to be powered on and remains on, despite possible test failures. This can be very useful for...

Guidance for Veeam Data Cloud Customers in Middle East Regions

Summary Veeam is monitoring risks that may affect cloud infrastructure in the Middle East regions, including the UAE, Qatar, and Israel. Customers using Veeam Data Cloud services in these regions should review their data resilience requirements and consider whether additional geographic separatio...

File-Level Recovery (FLR) in Veeam Kasten for Kubernetes

Purpose This article documents how to perform enterprise-grade protection and granular recovery of Kubernetes workloads using Veeam Kasten for Kubernetes integrated with Veeam Backup & Replication VBR. It provides step-by-step guidance on creating backup policies, exporting backups to VBR, and...

Veeam Recovery Orchestrator Vulnerability ( CVE-2024-22021 |  CVE-2024-22022 )

Veeam Software Security Commitment Veeam® is committed to ensuring its products protect customers from potential risks. As part of that commitment, we operate a Vulnerability Disclosure Program VDP for all Veeam products and perform extensive internal code audits. When a vulnerability is...

How to Test the Creation of Production Checkpoints in Hyper-V 2016 and Newer

Purpose This article documents how to force Hyper-V 2016 or newer to create a Production Checkpoint. Cause Forcing Hyper-V to create a Checkpoint in ProductionOnly mode is used as an isolation step when troubleshooting a Veeam job that fails to create a Recovery Checkpoint with Application-Aware...

Veeam Intelligent Diagnostics signature UID field

If you are not using Veeam ONE or your Veeam ONE server is not connected and monitoring Veeam Backup & Replication, you will not have a VID to enter during case creation. Simply leave the field blank. Purpose This article provides answers to frequently asked questions about the "Veeam Intelligent...

SQL VSS writer fails for SQL localdb on Azure AD Connect Sync server.

Challenge Backup or replication jobs with Application Aware Image-Processing enabled may fail on the server hosting Azure AD Connect Sync with an error indicating the SQL writer has failed. After the job has failed, running "Vssadmin list writers" from an administrative command prompt on the Azur...

Could not invoke guest operation error in a job when using vSphere API for Guest OS connection

Challenge When Microsoft User Profile Disks for example, in a Windows RDS farm are used, Veeam Application Aware Image Processing through vSphere API may fail with the following error: Could not invokeguestoperation. Cause When processing Guest OS data through vSphere API, Veeam needs to deploy a...

0x80042316 or Error: VSSControl: -2147212522

Challenge A backup job using Application-Aware Processing fails with the errors: Failed to create snapshot. Error code -2147212522. 'Backup job failed. Error VSS error: VSSESNAPSHOTSETINPROGRESS. Code:0x80042316 Solution Error code: 0x80042316 and Error code -2147212522 both represent the VSS...

File is locked by running session

Challenge A job or task within Veeam Backup & Replication displays the following message: File is locked by running session jobname Cause When tasks run in Veeam Backup & Replication, the files accessed by those tasks are tracked within the configuration database to prevent collision. As tasks ar...

How To Enable DDBoost Immutability with Governance Mode

Purpose This article provides additional information for enabling immutability for the Dell Data Domain deduplicating storage appliance when using governance mode, as referenced in the Veeam Backup & Replication User Guide here: Veeam Backup & Replication User Guide Backup Infrastructure Componen...

403 Forbidden Message When Accessing Veeam Data Cloud App

Challenge Attempting to load the Veeam Data Cloud app webpage fails with the error: 403 Forbidden Microsoft-Azure-Application-Gateway/v2 Cause The HTTP status code "403 forbidden--you don't have permission to access this resource" is displayed when a web server recognizes a user's request but is...

Release Information for Veeam Backup for Microsoft 365 7a Cumulative Patches

Requirements This Cumulative Patch can be used to: update manually from a previous Veeam Backup for Microsoft 365 7a release to the latest Cumulative Patch. upgrade an existing pre-7a Veeam Backup for Microsoft 365 server to Veeam Backup for Microsoft 365 7a with the latest Cumulative Patch...

Backup and Replication jobs fail with the following error: "CDeviceBase: resize is not supported. Failed to download disk"

Challenge Backup and Replication jobs fail with the following error: "CDeviceBase: resize is not supported. Failed to download disk". The following conditions must be met: 1. Veeam 8 Update 2 8.0.0.2021 or later 2. Backed up VM is running on ESXi 5.5 or later 3. Hot Add transport mode is used 4. ...