Trying to add Hyper-V System Center or Failover Cluster or Host: The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)

Hello Tales,
I see that you already tried several important steps. Sometimes I see problems with UAC remote restriction. I'm not certain that this will resolve the error but it is a function that could interfere. Below some steps about it.

Regarding the VM changing Nodes and making the backup job lose it's reference, I recommend creating the job in vRanger in the Parent object (The Cluster icon) instead of creating it on the Host or alternatively create a Backup Group (add the desired VMs to protect to it, then create the job on it), that way the job will follow the VM independently of the node where it moves to.

To disable the remote UAC, an entry will need to be made in the registry of the affected target node:

• Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
• Create a DWORD value called LocalAccountTokenFilterPolicy and assign it a value of 1.

A reboot is recommended after creating the entry but try connecting it to vRanger right away just in case.

Windows Registry Disclaimer:

Quest does not provide support for problems that arise from improper modification of the registry. The Windows registry contains information critical to your computer and applications. Make sure you back up the registry before modifying it. For more information on the Windows Registry Editor and how to back up and restore it, refer to Microsoft Article ID 256986 "Description of the Microsoft Windows registry" at Microsoft Support.

Hi Miguel.
Thanks for the info.
I can change the registry key on the VM without a sweat.
But if the best practice is to do invoking the Cluster, the best way is to ADD the cluster to Inventory.
I'm not able to do that due to an error: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))
This happens when I try adding either a Hyper-V System Center or a Failover Cluster

Hello Thales, 

No problem, but the registry key is actually for the Hyper-V hosts, not the VM. That key is to try resolving the Access is Denied error. 
Sorry for the confusion.
Yes, the best practice is to add the cluster to the inventory, that way you could resolve the problem with the moving VM too by protecting it at cluster level instead of host level 

Hello Thales, 

No problem, but the registry key is actually for the Hyper-V hosts, not the VM. That key is to try resolving the Access is Denied error. 
Sorry for the confusion.
Yes, the best practice is to add the cluster to the inventory, that way you could resolve the problem with the moving VM too by protecting it at cluster level instead of host level 

Miguel, I did the registry tweak with no luck. I'm getting: The machine does not appear to be a valid Hyper-V host.  Please check that the Hyper-V role has been correctly installed on it.

Hello Thales.
Please check if you have a duplicate IP, it might be another server replying.

It's not Miguel. Server have fixed IP.
I gave up on that and now I'm focus on adding the SCVMM but I'm struggling to install the console on vRanger Server.
This is the error I get when I try to add a SCVMM:
"System Center Virtual Machine Manager Admin Console must be installed and the vRanger service restarted before attempting to add SCVMM connections."