Ok, I thought it was my 5 year old PC that caused the problem. But even on my brand new top notch computer the launcer is still broken.
I really really love this game, but I can't play it. Yesterday I installed it on my new computer and I could open it. But today it's giving the same problem I've had on my old PC.
So..... screw it. I'm not returning to this game and I'm certainly not going to buy the expansion.