@seaspiritnw What file did you find, as in, what's it called, and what happens when you try to delete it? Please post a screenshot of the error or write out its full text.
Please also search your computer for your missing library items. The most thorough way is to download Everything, from VoidTools, which is a free and reliable search tool. Install it and search for Tray , then post a screenshot of the results. If the window is too narrow to show the full file path, expand it sideways until you can see everything.
Additionally, please list the full path to the user folder Sims 4 is currently reading. Here's how to find it:
https://sims4.crinrict.com/eng/2018/07/how-to-find-your-user-folder/
Please also let us know whether there's anything else missing, for example other saves or mods and custom content.