I have the issue as well. Every day I get that about 3 to 4 times. Very annoying.
I tried log in on Rohan web site before loading the game. I also d/ced by myself when I relog once I got that problem. It seemed to work, but only for a few hours and it starts again. I don't think it is a connection problem. I use wireless on both my comp and lap, and sometimes even though 1 gets the problem, the other is fine and vice versa (both login different accounts).
My suspect is however the event. I notice that it happens to me especially a lot after the forging event. At first, there is no problem at all. After my first forging event, it starts, and unfortunately won't stop >"<
Also, there is a bigger chance of having the error when I'm hunting on fields rather than sitting at cities selling.