Recoverpoint for VM, Error on Cluster Registration

Hey there

Actually we going to buy RP4VM, so we decided to test it first...

But after complete installation of RP4VM 5.1sp1, Its time to Register ESX Cluster from the location:

 

RecoverPoint for VMs / Administration / vRPA Clusters / ESX Clusters


And then VALIDATE the added cluster., but Exactly after hitting the Validate, an ERROR appear with just an OK, nothing else. i attached the screen shot, can you please help?

 

*its necessary  to test this things before buying more than 400 of LICs...

vrpa.PNG.png