The cause of most NFC errors fall into 4 primary categories:
(The proxy or Veeam server cannot resolve the ESXi host)
- Port (902)
(The proxy can resolve the IP, but port 902 is blocked)
(The account specified in [Backup Infrastructure] for the vCenter does not have permissions)
- File Locks
(The file Veeam is trying to read is locked within the vSphere environment)
*If the account that Veeam Backup & Replication is using to communicate with the VMware Environment has granular permissions set, please confirm all permissions are set according to the Granular Permissions Guide.
Due to the nature of NFC as a client<->server type connection, there is also potential that all things may be correct on the Veeam client-side, and there exists an issue within the VMware Infrastructure itself.