At first the game worked fine, then recently it started crashing and freezing. It's very frustrating. it freezes at the 3rd min mark during the hard challenges. It happened a few times. In another instance I used a Tear of Ancestors to summon a hero and got an error msg that said invalid parameter and didn't get the hero. I sent a note to tech support and I'm getting the run around. Just replace replace the thing & stop wasting time. Worst part was it froze during Alliance War got 0 points.