I have frozen on the Urzael fight twice now. No problems any other time. Not sure if it's related.
# 1 Dec 16, 2013
# 2 Dec 16, 2013This may be related to the game trying to stream additional data, or there could be some sort of problem with your installation of the game. You might try to re-install the Reaper of Souls client (ensuring you don't attempt to play until the download bar reaches the "Green" phase) and see if that helps to resolve the issue.
I am going to go ahead and move this thread to the RoS Beta Tech Support forums. You may be able to find additional troubleshooting suggestions over there.