When the first time I found out my pc cannot connect any of the game server including the crpg mod, native, and napoleon war, I tried to let the steam fix itself( you know what to do if you play this game on steam, right click on the game choose properties blablabla), and it's work on any of the other game mods except crpg, also you will lose all your change on the game file ( so I had to reinstall the gk bundle on native).
We might need to fix some files on our pc, and/or crpg servers need to be updated, in order to get connection on both side.