We had a power outage over the weekend and everything is working again except for the GP clients. After they log on, it hangs and eventually comes up with an unknown error. The reason for that is because the firewall in server 2008R2. I have GP traffic allowed on the server. If I turn the firewall off, GP client connects without a problem. I am using the domain networks location settings in the firewall. Does anyone knows why the firewall is blocking GP?