Clock froze,sims stuck in loop, but surroundings kept going

Well this was useless. I have this issue and no I don't have any mods. Game clock starts at 2:02 am and goes to 2:45 am wherein the clock stops but all animation continues. Nothing cna be interacted with, pressing pause still shows active animation, going to build mode still shows active animation. Save does not work. Exit does not work.  I have to control alt delete to get out.  It has done this a dozen with no change