I was already playing with something similar over in this post here: veeam-endpoint-backup-f33/recovery-environment-can-t-reach-unc-path-t25389.html
This is the exact error received if credentials are not entered:
There is definitely a bug going on I feel. Pass-through of the logged on credentials (for AD-credentials on an NTFS-protected share) are not working; if that is even an option? It is not very clear.
However, If i check the 'This share requires access credentials' and enter an account that has access to the shared folder, it works fine. It also seems to cache the credentials, since I was able to backup, go to the Backup Settings, uncheck the box, and it still backs up fine. Also, the Populate button works, as long as credentials are entered (or 'cached' as I noted previously). However if I change the share, the credentials are lost, and backups/populate fails.
Should I submit a case for this?