I just wanted to hop on here to say that I'm also having this same issue, and for me it also seems to have coincided with this most recent patch as it never happened before then. The symptoms are the same as what OP described. The game will suddenly freeze and then nothing on the PC is responsive. I can move the mouse around but all keyboard input is locked up and clicking on anything doesn't work. For me, this is usually after the game has been running for several hours, and has always occurred when I have started to cast something. The only thing I can do is forcefully shut the computer down by holding the power button and then it works fine again for the rest of the day.