[Current Issue] Sims 3 "serious error" when loading save

mtoliver26​  Are you seeing the "serious error" message or something else?  If this is about the "serious error," did you create a new, local, admin Windows account for testing?  An account is only local if it is not linked to a Microsoft account or any email address; an account that does have one of these links is not local and therefore not a valid test.