Veeam B&R 13.1 xcp-ng error

[arcatlantic]

I have setup B&R 13.1 on a windows client, and connected to xcp-ng pool. I have removed all previous backups from previous beta 1 tests. Initial full backup was successful no issues. On first delta backup 4 out of 7 vms have this warrning / error...


8/5/2026 5:34:50 PM Warning : Failed to use CBT: [Task e75c4247-2ee1-7b51-088c-b970ace60f3d (Async.VDI.list_changed_blocks) failed: . SR_BACKEND_FAILURE_460. . Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]

[Mildur]

Hello,
That sounds like a technical issue. We cannot investigate such issues through a forum topic.
Please provide a support case ID for this issue, as requested when you click New Topic. Without case number, the topic will eventually be deleted by moderators.

Best regards,
Fabian

PS: support can only help if you upload logs https://www.veeam.com/kb1832

[arcatlantic]

I am listed as the only admin on the account and I am unable to create a support case for our licensed product. I have opned this case - Veeam Support - Talk to Manager # ESC0161498 about that specific issue.

[Mildur]

Since this is not a support forum, it is important that you regain the License Administrator role so you can manage case administrators. As soon as you have assigned yourself license or case admin, you will be able to open support cases for your own license.

In that case, please follow this KB article on how to regain access to the License Administrator role:
- KB2211 - How to Change License Administrator

if you have lost access to the License Administrator account or want to change who is assigned as the License Administrator, please create a licensing case.

When requesting a License Administrator change, please include the email of the new License Administrator.

Note: If you are not a Case Administrator for the Support ID whose License Administrator you are attempting to change, leave the Support ID field blank.

Regarding your escalation, the team behind this forum is not able to see it, since we are not part of the Support department.

Best,
Fabian

[ronnmartin61]

@arcatlantic like @Mildur says best to work this through support. There is one known snapshot issue that I'm guessing could possibly have this side-effect (noted in the release notes BTW). We take standard Xen snapshots for CBT but then immediately rename them with our own naming convention. We've noticed that sometimes this rename operation returns success status even if it fails. In this case I can see how this might throw this sort of error but again best to confirm w/support.

[arcatlantic]

Account issues have been reseolved so i am now able to create a support ticket. There was a problem with the account preventing me to do so.

Case #08188639