University Students reset when sent to class

[Rubyelf]

So just recently out of the blue, after installing the latest crap from the store (the new hood and the toyshop), my sims have run into an annoying bug. Whenever I try to get my sim to go to class, it resets the sim and I get a message saying "there is no class right now, come back later".  I tried uninstalling all my CC, including the store CC, but I am still encountering this issue, only with this save game, if I go back to an older version, the sims successfully go back to class with no issue. I have however found a work around in the interim, which involves going back out to the main menu and then going back into the game- which makes them successfully go to class.

Does anyone have a clue what might be the issue here? Or has my hood just decided to froober itself for no reason?