Playing on Firefox 21.0. I was swimming when I got the ‘An error has occurred’ message. I couldn’t move from the square. I saved and reloaded, and the surrounding squares were black and I couldn’t see the bottom section of the HUD. I still couldn’t move, but I could gain swimming skill and eat. After eating and continuing to try to swim, it finally let me move, but the bottom portion of the HUD was still gone. A reload from this state brought the HUD back. It appears to be playing normally from this state.