Veeam Agent Error Reconnectable protocol device was closed

[Jan1987]

Hello

I have a problem with the Veeam Agent under Windows 11 24H2.

Until now, the backup always ran smoothly without any problems, even since the update to Windows 11 24H2.
Since 08.01.2025 I now get the following error:
“Error: Reconnectable log device has been closed. The command to transmit the next block could not be retrieved. Number of blocks already processed: [12]. The download of the disk 'b73eec5f-f1b0-40f5-9da1-859bef4b9aad' failed. write: An existing connection was closed by the remote host Failed to upload disk. Skipped arguments: [EmulatedDiskSpec>]; Agent could not process the method {DataTransfer.SyncDisk} ”

What have I already tried:
- Reinstall Agent
- New backup job created
- Checked disk for errors.
- Network cable checked.
- Driver updated

Version Veeam Backup Server: 12.3
Disk check on the backup server and repository revealed no errors, only this one client device is affected.

There were no changes to the network or firewall.

I hope that the community here can help me. The setup is a LAB with NFR license. Case ID #07564561

Greetings
Jan

[Mildur]

Hello Jan

Reading the error message it looks like issues regarding the source disk.
But unfortunately, we cannot troubleshoot technical issues through our forum, as outlined in our forum policy. Please wait for our support team to respond to your support case according to the provided SLA policy for users of our free product (support on best-effort).

Thank you for understanding
Fabian Kessler