Something is blocking your communication to the patch server. Check your local security logs to make sure there isn't an exception being logged when you are launching and trying to update. It may not be something local either--could be something on the other side of the modem mistakingly blocking the content as suspicious traffic. Could try a free trial of a VPN service to see if it bypasses such shaping. Keep in mind that the free trial may not provide enough access for a large patch (some limit to 500MB or just a few hours at a time)--this would be more to test if you regain connectivity after encrypting the data through the tunnel, which would indicate your ISP or one of their routing partners may be filtering the traffic and causing the problem.