I tried creating a brand-new protection group, and adding a linux (centos7) guest to it. Nowhere in the wizard does it ask me whether it is windows or linux, so I assumed it can (somehow) figure it out. Unfortunately, no. It then bombs out due to a bad network path (syntax looking windows related.) Am I missing something here?
p.s. if I try the 'Test' button, the next screen mentions checking Windows credentials, which seems wrong
I cannot say that without have a look on the backup server. I think, the solution will be very simple.
Please open a support case by veeam. They can help you very fast to resolve this.
If you use a user from Type (Linux Account), then Veeam Protection Group will work as expected. If not, this is a bug for the veeam technical support.
As Fabian mentioned we determine the OS type based on the account, so just to be completely sure I'd try to recreate the credentials from scratch. Cheers!