I too have this issue. I did have mods but I deactivated all of them and have attempted to play a vanilla game. Even in this game when I or my sim choose an action I can not interrupt or cancel that action. At first it looks like it will cancel the action with the mark through the action but then it just continues. My sims will die from chatting with eachother, playing chess, dancing, using the computer....... Any action which does not have an automatic end built into the action (such as cooking a meal, showering, using the restroom, eating) will over time kill the sim. I have reset the characters and that is the only way to cancel actions.. but honestly who wants to play a game where every 2 minutes you are resetting your entire household? The only thing I haven't tried at this point is a whole new install.