GalacticGal Rename the Sims 4 folder you're currently using so there's no "The Sims 4" folder in Electronic Arts, and try to play. Let me know whether the game works. If it does, start moving or copying some content to that new folder and keep testing.
If you can't play after renaming the folder and before adding any content to the new Sims 4 folder (or if no new folder is created), please provide a dxdiag. Hit Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop. From there, you can attach it to a reply using the paper clip (Attachment) icon included with the other formatting buttons.