Odd behavior of Tree Creator texture

Hello! I'm new to Unity and I'm already in trouble - when I try to modify the imported version of BigTree from Tree Creator in any way it gets some weird white texture on it. The problem doesn't go away in Play mode. I guess the solution is simple but those are my first days with Unity. On the right correct tree, on the left TC with any modification. ![http://s29.postimg.org/5pijr8e5j/problem.png][1] [1]: http://s29.postimg.org/5pijr8e5j/problem.png Thanks for your help :)