Hyper-V Backup jobs failing with an error "The system cannot find the file specified" after upgrade to Veeam B&R 9.5 Update 4

Challenge

After installing Veeam Backup & Replication 9.5 Update 4, Hyper-V backup without application-aware processing may fail with the error "The system cannot find the file specified".

Cause

This issue is caused by the snapshot path in the VM 's configuration being different from the actual path on a file system in terms of symbols capitalization. You can confirm this by comparing paths in bold in the Task.<VM NAME>.<VM UUID>.log file:

[22.01.2019 19:39:09] <28> Info                   [AP] (65e8) output:     <snapshots>
[22.01.2019 19:39:09] <28> Info                   [AP] (65e8) output:       <data_root type="string">C:\Temp\<VM name></data_root>
[22.01.2019 19:39:09] <28> Info                   [AP] (65e8) output:       <list>
[22.01.2019 19:39:09] <28> Info                   [AP] (65e8) output:         <size type="integer">0</size>
[22.01.2019 19:39:09] <28> Info                   [AP] (65e8) output:       </list>
[22.01.2019 19:39:09] <28> Info                   [AP] (65e8) output:     </snapshots>

[22.01.2019 19:39:09] <11> Info [AP] (65e8) command: 'file2text\n\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy16\temp\<VM NAME>\Snapshots\<VM UUID>.xml\n2097152\n'
[22.01.2019 19:39:10] <10> Info [ReconnectableSocket] Stop confirmation was sent on [c1d84e94-b09b-4039-a8dc-4973e12934fc]. 
[22.01.2019 19:39:10] <23> Error [AP] (65e8) error: The system cannot find the file specified. 
[22.01.2019 19:39:10] <23> Error Failed to open file [\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy16\temp\<VM NAME>\Snapshots\<VM UUID>.xml] in readonly mode.

Solution

There are two methods for correcting this issue depending on your preference:

1. Change snapshot path in VM configuration manually:

1. Connect to the Hyper-V host and go to VM Configuration of VM in question;
2. Go to Checkpoints tab and choose ‘Browse…’ underneath the snapshot path;
3. Update the path.

2. Install a hotfix for Veeam Backup & Replication 9.5 Update 4 (build 9.5.4.2615):

1. Ensure that all jobs are in a stopped state.
2. Stop all services on the Veeam Backup server that begin with Veeam. (PowerShell: gsv Veeam* | spsv )
3. Navigate to the Veeam installation folder on the Veeam Backup Server (by default it is C:\Program Files\Veeam\Backup and Replication\Backup)
4. Rename the Veeam.Backup.Core.dll file to Veeam.Backup.Core.dll_backup
5. Replace the files listed in the previous step with those found in the hotfix package
6. Start Veeam services on Veeam Backup server. (PowerShell: gsv Veeam* | sasv )

More Information

[[DOWNLOAD|DOWNLOAD PRIVATE FIX|https://storage.veeam.com/Fix_159310_2015be7f9e.zip]]
MD5 for Veeam.Backup.Core.dll: a0d5b70a85f9b5086d297bf2267d8bb5

Should you have any questions, contact Veeam Support.