With VC5.5U2 and above, GRE UI is changed from Flex to Angular and it has gone Agentless.
So probably you need to:
- Delete (with remove components) the VCenter client from DP Cell manager
- Restart VCenter service and Vcenter webclient service in VCenter server.
- Install VMWare Granular Recovery Extension agent component in Cell manager or any other Host part of the cell. This will act as the mount proxy. (Mandatory pre-req)
- Import the VCenter again to the cell along with select "Advanced GRE Web Plugin" tick box
- Close, clear the cache and open the Web Browser; Open VCenter Web client.
- In VM-> Manage -> HPE DataProtector -> Settings : Set the mount proxy path
Now you can proceed to Recovery.
Hope you are using VC5.5U2 or higher and firewall is disabled or configured for the ports in use.