What browser are you using? I remember something similar with chrome. It would get upto the loading bar sometimes but would take a dozen or so refreshes to get further. It got the the point I stopped using Chrome for grepo and switched browser to ff.
May I suggest you just do not bother with grepo and play a better more balanced game instead. If you simply want to spend HUGE amounts to win, then this game is for you. If you actually want FUN and to enjoy a game. Simply move on sir.
Grepolis is the best game I've played and there are so many games that give premium users a much larger advantage than this game does.
Have you tried opera browser? That one always worked well for me. If that doesn't work then please send a ticket in to the support team and we will help you to resolve your problem.