Game cannot be paused, sims keep going, time stands still

Dear Simmers,

Since a few days I have the following problem. This happens quite quickly once I start my game. My Sims keep doing what they are doing, continuously. Can't be stopped via pause, via the cheat or via debug Sims. You can also no longer save your game. You can still build to it, but that won't be of much use...

I've taken out all my Mods and other things, but still the same problem.

I can then only exit the Sims by pressing crtl-alt-delete and then end the task.

Help?! Does anyone have a solution and are you experiencing it yourself?