CC Tray files not appearing in-game.

LifeOn_Sims4​  If you add another household or lot from the Gallery, or save one of your own, do any new files appear in this Tray folder?  I ask because it looks like you've only added two items to this folder, and it sounds like you've tried more between using the Gallery and installing your own files.  It's possible the game is reading a different folder instead.  So please add some item from the Gallery or your own game and see whether you get any new files in this folder.

If you don't see new files, please find the full path to the folder the game is reading, as described here:

https://sims4.crinrict.com/eng/2018/07/how-to-find-your-user-folder/

Then add the Tray files you download to that folder.  If one item doesn't work, remove its files and test another.  And make sure the "include custom content" box is still checked when viewing your Library.

puzzlezaddict​ Hello! Yes, when I download files from the gallery, these files appear in my Tray folder. It's only when I download custom cc Builds/Households. I know these files that I download are not corrupt, as they work in my friend's game. I have also tried Game repairing everything, so I'm not sure what's going on.

LifeOn_Sims4​  Try using a different browser to download them, preferably a new one or one you never use just to make sure your settings aren't interfering.  Firefox is pretty good about not corrupting downloaded files if you'd like a suggestion.

Please also double-check that the downloads are base game-compatible or at least don't use any packs you don't own.  For example, a household with a pet probably wouldn't show up if you didn't have Cats & Dogs installed.

puzzlezaddict​ I have just tried using the Firefox browser to download an apparently base game only house, and it has still not appeared in my Library with CC toggled on and correctly placed into my Tray folder.

LifeOn_Sims4​  Alright, let's try a clean user folder next.  Move the entire Sims 4 folder out of Documents > Electronic Arts and onto your desktop, launch the game to create a new folder, quit (at the Main Menu is fine), download a fresh copy of some item, and put its files in the new, now-empty Tray folder.

Your saves and other user content won't be read by the game, but everything will be intact in the folder you moved and can be restored later.

If you don't see a new Sims 4 folder, you didn't remove the one the game is using.  If you see a Tray folder with items in it already, in exactly the same location as the Sims 4 folder you removed, then OneDrive may be downloading online copies of your files that it had previously synced.  In either case, let me know so we can address that specific issue.

Otherwise, place the files in the Tray folder and load the game to see whether the content shows up.  If it doesn't, please test in a new admin Windows account.  Make it local, as in, don't link it to your Microsoft account or any email address.  You'll be able to launch the game without reinstalling anything.

puzzlezaddict​ Hello! I moved the Sims 4 out of the folder and pressed play so it'd create a new folder. I exited the game and placed the new tray files in, relaunched, and it still did not appear. I'm not quite sure how to test in a new Windows admin account, as when I go to add another user, it asks me to provide an email, and there is no option not to provide an email.

LifeOn_Sims4​  You should be able to select "I don't have this person's login information" or similar.  It might be in very small print—Microsoft tries very hard to get people to link their email address.  But the option does still exist according to the documentation.