World installing as Object, not World

@HSmith2016  When a world download first looks like it's finished, it shows as an object, not a world.  It can also look like that if you reuse an old download, or don't remove a previous download from the Downloads folder.  The trick here, aside from using fresh copies, is to wait 5-30 seconds for the icon to change to a preview of the world, and only then try to install it.

When you download an item from the Store, no matter what it is, the file lands in Downloads.  This is what the launcher's Downloads tab reads.  It's only after installation that a file would be created in InstalledWorlds (worlds) or Library (venues, or households or lots from the Exchange), as well as DCCache (the .ebc files are bundled Store content).  This is normal.

What I would suggest here is installing your Store content into a clean folder, slowly and carefully.  Here's how:

https://answers.ea.com/t5/Store-Issues/Read-First-Sims-3-Store-guide/m-p/13479922#Clean

As described, you can transfer your saves and anything else you'd like to keep to the new folder after you've confirmed that your Store content is working.

If you can't install even one world in the new folder, try using a different browser to download it.  Firefox usually works better than Chrome or Edge.

Thank you, I'll give that a try. 🙂