Firstly check your firewall and anti-virus for blocked content. Add a firewal exception to windows firewall for the following address and port.
If this is only effecting you after an update, delete the game profile in the following directory, then delete the interfacedata.dat file in your games local directory.
Game Profile - C:\Users\%user%\AppData\Local\dof
Steam Users Game Directory - %Drive%:\Steam\SteamApps\common\Dawn of Fantasy\interfacedata.dat
Non-Steam Users i assume it somewhere in your C:\Program Files(x86)\Dawn of Fantasy -for 64 bit os
For you lucky XP folks who have the game working should be C:\Program Files\Dawn of Fantasy
Both a new interfacedata.dat file and Game profile will be created with defaults when you run the game. You will have to save your login info again if you wish.