this used to happen to me but i jus gave the page time to load properly helped me but most problems are to wid java in my experience try downloading latest version

What do you mean press the button to start a game? And what is the first page?

If your refering to selecting the room you probably have a pop-up protector on your computer. Or if you mean accepting a challenge or sending a challenge then I may have no idea what is wrong. I read the blue writing that often tells me whats happening.