The Sims Teamoh it gets better it locks you into a re occuring load for all your packs that's why you can't play. says can not play until all packs are loaded in that you selected. But they never do load in is'nt it fantastic :D.
I've split your post from the Mod related thread you posted in here as you're referencing the new Pack selection addition in Game Options.
Does your issue occur in a completely clean game? That is a game where you have renamed the Sims 4 folder and the game has created a new one.
Did you repair your game?
says can not play until all packs are loaded in that you selected.
A screenshot of this error you're referring to would be really helpful please.
