so I added three

@lucymonic  For the "finalizing" message, run the Origin reset tool for macOS:

https://help.ea.com/en-us/help/origin/origin/how-to-reset-origin-on-mac/

For the game itself, start by running the Super Patch (digital download version).  Even if you patched before, it's a good idea to to it again, and running the Super Patch on an already patched game won't hurt.

https://bluebellflora.com/sims-3-manual-super-patch-for-mac-1-67/

If the three new packs are properly installed, you should have an icon for each one in Applications\The Sims 3.  (Please check, and if you don't see the icons, let me know.)  Assuming the icons are there, the only thing you should need to do is copy folders from Ambitions and Late Night into the folder for University Life, your newest pack by release date.  This video shows you how to do it:

https://answers.ea.com/t5/The-Sims-Mac/CURRENT-ISSUE-Sims-3-Unknown-Error-in-El-Capitan-Sierra-High/m-p/5725514#M5926

If you still get an unknown error, or something else goes wrong, please list your Mac's specs, as described in this post:

https://answers.ea.com/t5/The-Sims-Mac/READ-FIRST-Sims-3-Mac-Help-Guides-and-Troubleshooting/m-p/4756624#M4

so I did the reset origin and my sims  game is up to date  but it still said that my game isnt installed but I can now at least open it without getting the unknown error message. the only thing is is still says finalizing on my expansion packs generations and high end loft stuff. the other expansion packs are all uploaded and shows at the Bottom of my game launcher. how do I get my last two expansion packs uploaded now ?

@lucymonic  You don't have to play through Origin at all; just double-click on the University Life icon in Applications\TS3 and open the game that way.  (You could even uninstall Origin if you wanted.)  But if those two packs aren't showing up in-game—you can check Buy mode to see if their content is present—you'll need to uninstall and reinstall them.  The uninstaller that comes with the game is often useless, so here are instructions for uninstalling manually:

https://bluebellflora.com/manually-uninstalling-an-expansion-or-stuff-pack-in-the-sims-3-for-mac/

Keep in mind that if you use the uninstaller and don't reinstall those two packs, you'll get another unknown error.  In that case, the solution is to either install the packs, or to remove the hidden Library files as described in the link above.

it shows I have them and when I redownlaod them it says I need to download sims 3 it just says finalizing on two packs ive done the uninstall already as well along with the reset origin 

this is what it shows whenitry to upload my expansion packs have delete and uninstalled the game. I have used the reset origin download and I have went through the files and deleted the ones they said I should not sure what else I can do to get my last two expansion packs downloaded if it says that dont have the base game downloaded which I do. I can open the game but cant finalize the two expansion packs. Anyone have any advice that could help.

@lucymonic  Can you play the game?  (without opening Origin)  Are all your packs working correctly?  Then you're fine.  If not, please let me know exactly which content isn't working, and what you're not seeing that you should.  Origin is annoying, but it can be ignored.

Two of my expansion packs aren't working the generations and the high end loft stuff. It says finalizing I will  include pictures but I can play the game and I dont need to open it through origin. the pictures are what I am seeing on my screen when I try and finish downloading the expansion packs

@lucymonic  Alright, in that case, I think you do need to go through with a clean uninstall (sorry).  I don't know what exactly is causing the error, but if running the Super Patch didn't help, the only other way to deal with this is to start from scratch.  Here's how to do a clean uninstall:

https://bluebellflora.com/how-to-do-a-clean-uninstall-and-reinstall-on-a-mac/

Once you've done this, reinstall the base game only, then run the Super Patch again.  Next, download only High-End Loft Stuff.  If you get the same error, let me know.  If not, go ahead and install Generations, and test again.  If everything works, install your other packs, copy over the folders for Ambitions and Late Night into the folder for University Life (as shown in the video), and create aliases for Ambitions and Late Night in Applications\TS3.  Here's how:

https://bluebellflora.com/sims-3-packs-not-showing-as-installed/

There's a way to install without involving Origin, although of course you need Origin to download.  It's a bit complicated, but it might help in this case.  If you can't install HELS or Generations the normal way, I'll write out the workaround.