Need Help with Saves in the Sims4

@Kittisu  When you upgraded to Windows 10, did you do anything to make sure your user files were preserved?  It's certainly possible to do so, but if you simply wiped the drive and installed Windows 10 fresh, all your user data would be gone.

Another possibility is that Windows 10's OneDrive uploaded your files to cloud storage.  Sims 4 can't access OneDrive's version of Documents, so it would have created a new, empty user folder in the local version of Documents.  If you do have OneDrive running, just look for any Sims 4 content there, and move it back to the proper location, as in, your local version of Documents > Elctronic Arts > The Sims 4.

If neither of these is the issue, try searching your computer for any saves.  Open a File Explorer window, click This PC in the left panel, and enter Slot_ in the search bar in the upper right corner.  If the search finds any saves, click on one, click "Open file location," and you'll jump to wherever the file is.  Here again, you can move any saves or other Sims 4 content you find to the correct location, and the game should read it again.

Hi! Thanks for replying. I did not delete any files when I upgraded to windows 10, everything was kept the same. I also deleted OneDrive when I saw that it could’ve been the culprit but after uninstalling it and verifying my sims4 file locations, it’s not the problem. I searched slot_ on my computer, no results. I even uninstalled Sims4, reinstalled - menu buttons are still gone. This is incredibly frustrating, I feel like another option I may have is to delete everything to do with sims4, uninstall and start over fresh with new folders but hopefully it doesn’t come to that. 

@Kittisu  Uninstalling and reinstalling the game won't help.  The Load Game and New Game buttons only appear when at least one save is present, and you somehow no longer have any.  I'd still check OneDrive: it's possible that your Sims 4 data was uploaded in the brief time between when you installed Windows 10 and when you removed OneDrive.  You don't need to activate it: just go to onedrive.com , sign in, and check your cloud storage.