While helping some Pards get used to creating a game or joining a game (no expert yet) we found that if you have a problem and didn't click the right thing you can start over by refreshing the page. This also worked when we finished and it wouldn't let you leave after clicking on the leave button. The main problem is the many clicks before entering a game or hosting a game.
Clicking start, then d/l file, then clicking start then clicking run and then clicking run again. one mistake in this sequence will freeze you quicker than saying Jack Frost. But refresh the page and voila' ya start all over. So don't panic like I did lol.