Starting with Veeam Backup & Replication 9.5 U4, the Veeam vPower NFS Service uses an IP allowlist to control which servers can connect to the NFS share. In some rare cases, Veeam Backup & Replication may not add the IP address of the ESXi host to the IP allowlist.
To isolate whether this is occurring, it is possible to disable the IP authorization control system by creating the following registry value on the Mount Server.
Please note that this value disables built-in IP authentication for vPower datastore and is only recommended for testing purposes.
Key Location: HKLM\SOFTWARE\WOW6432Node\Veeam\Veeam NFS\
Value Name: vPowerNFSDisableIPAuth
Value Type: DWORD (32-Bit) Value
Value Data: 1
After creating the above registry value, restart the Veeam vPower NFS Service.
Retry the restore operation with the above registry value in place on the Mount Server associated with the repository where the backup files are located.