al6xis These are all the entries? It's odd because there's no folder in __Installer anywhere, and there's also an EP04 folder here:
C:\Program Files (x86)\Common Files\Steam
I have no idea what that folder is for, but try deleting the EP04 folder inside, with the EA App and Steam both closed. Then clear the EA App's cache (again, if you have already):
https://help.ea.com/en-us/help/faq/clear-cache-to-fix-problems-with-your-games/
and see whether you can reinstall the pack. It should go into the game's program files this time:
C:\Program Files (x86)\Steam\steamapps\common\The Sims 4
The folder in Delta can be ignored for these purposes.