http://imgur.com/a/GNbpT FireEaters can walk on the impassible terrain in the lava (the trees), and also cannot walk or leap out once they are on the impassible square, they are stuck. I did test to see if non-fire eater/non-flying champ could enter the terrain, and they cannot so it's just FireEaters/LavaWalkers. Happened to me in a match, and I went and tested it and screenshot it in the picture above. The second bug is that there is a random lava square that is dirt, and not lava at all. It's on the right side. (on an unrelated note, if someone could teach me how to post a screenshot directly to these forums that would be appreciated)
@Sokolov This seems relatively easy to fix, but looks like an underlying issue with lavawalker I suppose?
