Weird, can you describe what you were doing when that happens? Was it when you were opening up a world or ...
I want to fix this as soon as possible and I don't currently know what could cause it. I do know opening new worlds can cause freezes if the world is extremely large, but will bounce back after a minute or two. Quick question, did you explore a large part of the world / was exploring the world when the crashes happen? Also, I have another idea that it is ram related. In your task manager, have you seen the game use too much ram?