This is only for people who have Sims 4 base game on Orgin and Sims 4 DLC from Steam. Ok so to get straight to the point, If you have Base game sims 4 on Orgin , But have Expansions/Game packs/Stuff packs from Steam Sales and trying to download your steam Sims 4 DLC over to Orgin, you need to do it Manually.   The game will not run on steam just to clarify, if you try, it will just crash over to Orgin saying "ERROR Game not installed" Blah Blah Blah and you will have to repair the game