This has actually happened to me and you can get out! it is not so obvious how, I will explain... 1) Go up to one of the invisible walls, run against it for a bit to ensure you are fully against it. 2) Press vault (climb over) while facing the wall 3) As the animation starts of the character climbing onver nothing quickly hit esc and quit the server (must complete logout while the animation is playing) 4) Relog into a server and voila.......you should be out. This worked for me first time, if it doesn't work for you immediately, give it a few tries, it is important to be quick with the logout of the server.. Good Luck friend. Rowdy.