I think your problem may be isolated to your computer-as at least I didn't have any issues nor did the person I was with, when I joined the Tree of Life via the Team Up Box in Olde Town. Have you tried reinstalling the game? Maybe contact support if the problem persists.
Exact same thing happened to me this morning I was walking to to the guy (forgot his name) and it froze. I couldn't do anything, I tried turning off my computer and re-entering, nope. Tried a different character, indeed it works. Go back onto my Fire and it's still frozen. I waited about an hour and it sent me out and I had to restart but at least it stopped playing up