About the "Null pointer exception": I noticed this bug before, but I think, it never happened with me, that the game completely hung after that. However, there are some occasions, it seems, I can not continue my move. (And since the red bar won't disappear once onscreen and in most of my online games appear rather early, I can't say, if this is related to each other.) But there is an easy walk around in this cases: I just write something in the chat line (nowadays normally just "-"), and instantly after hitting return, I can make my move. (I noticed, that this works, because in the first few times, I simply wanted to notify my opponents, that the game is hung, and wrote some text in the chat line, which also instantly made me able to continue.)