I have uploaded worlds and see them in my Assets folder. When I try to load them into a game I can’t see them. Other worlds work fine. DnD5e rules
Is it just the assets you can not add to a game or is it the whole world that you cant find?
For assets, if you use the tile explorer (from inside Foundry) you should be able to navigate to your asset library and use the file picker to find them.
It sounds like you uploaded a world to the assets library, rather than to your game data storage. Use the import wizard if you want to import a world : Importing Worlds/Modules/Systems - W/ Video Tutorial
Other possibility for it not being visible in Foundry is if you imported a world that was ported to v10, and you’re running Foundry v9.