I can't connect to an ESXi 5.0 update1 host via the sphere client. I can connect to vCenter with no problems, and I can RDP into the VMs on the host with no problems. I can ping the host using the DNS name or the IP address, i can access the host via DCUI, but when I try to connect to the host via the sphere client I get the following error.

I as a result i can't add this host to vCenter either. I reset the host management agents, the management network also. I ran network test in the host's DCU and everything thing came back "Ok" with the DNS, Gateway, and Hostname. This issue started today, when there was a network issue and I believe the host became isolated (disconnected) and it's VM (disconnected), so I removed the host from vCenter and logged into the host via DCUI and reset the agents. The host and VMs were now pingable, but I can no longer access this host via the vsphere client nor can I add it to vCenter. Nothing changed in our network. I didn't try to reset this host since the VMs where running fine. I need to get this host back into vCenter so does any one have any ideas on fixing this? Thanks