Could not locate this item

Hello
The files of your builds and Sims households are kept in your tray folder in your Sims 4 folder. You may need to remove the files of the builds that are missing the images, and re download the builds again.
Each sims household contains 5 files and an extra file for each extra sim. ( 1x .householdbinary, 1x trayitem, 2x .sgi, 1x .hhi and an extra sgi file for each extra sim)
A Lot consists of 6-11 files, depending on how many floors your Lot has (1 trayitem file, 1blueprint file and 4 bpi files, and an extra bpi files for each extra floor).
Try to find the files that relate to the build that is causing the issue, and remove them from the tray folder. You can sort the tray folder by date /time and that can help you to find the files. The date will be on the build that is on the gallery,

You can’t put files into sub folders in the tray folder, as that will prevent the builds or Sims from appearing.
Try sorting the tray folder by date. Then look at the gallery and see what the date is on the build. Then go to the tray folder and find the files that were downloaded that day. This should help to locate the files for a build.

If you have game issues, you can start a new thread in the Tech or Bugs sections and post about the issue on the thread. This link explains about the site.
https://answers.ea.com/t5/General-Discussion-Feedback/Welcome-to-the-Sims-Section-of-AHQ/td-p/6931624

I don't have them in my tray folder. I just downloaded them from the Gallery. TBH, there are actually some lots that are in My Library that I don't remember saving from a particular user.

When you download builds from the gallery and save them to your library before placing them on the lot, their files automatically go into your tray folder.
If you are continuing to have issues after trying to find the files of the builds,you may be best to post on the AHQ EA Sims 4 site
https://answers.ea.com/t5/The-Sims-4/ct-p/the-sims-4-en

How should I ask on that website? Also, can you put the files into different folders in the Tray Folder so you can identify where the files come from?

Okay but also how should I ask on that website?