When getting this error; there are several solutions
In my case the destination server had the remote registry service crashed;
following the Veeam forums:
- Make sure the Windows time on the Veeam Backup server is the same as in the guest OS.
- Make sure you do not have a firewall in the way (you can try disabling it for testing).
- Make sure you can connect to the admin share (for example, \\Server Name\admin$) with the same credentials as provided to Veeam Backup &
- Replication for VSS.
- Make sure the VSS writers are set to automatic in the guest OS.
- Make sure you provide Local Administrator (MACHINE\Administrator) or Domain
- Administrator (DOMAIN\Administrator) account privileges.
- Make sure the guest OS is in the same network as the Veeam Backup server.
- Make sure File and Printer Sharing is enabled in the guest OS.
Once File and Printer Sharing is Enabled on the guest OS, ensure to provide permissions through Windows Firewall if applicable
- If the guest OS is Vista/2008 or later:
In the Network and Sharing Center, verify that it is not set for a public domain.
Verify that the Remote Registry Service is started.