Re: Sims 4 won't repair, EA app won't clear cache (Windows 10 PC)

@BuddhistToesZen  For the EA App, please use Revo Uninstaller (the free version is fine) to clean-uninstall it, then restart your computer and reinstall the App.  Try again to repair.  If it doesn't work, you may be seeing a variant of this issue, which also sometimes happens during the repair process:

https://answers.ea.com/t5/Technical-Issues-PC/DLC-download-error/m-p/12620575#M253001

For the red Xs next to your files, do you mean files within Documents > Electronic Arts > The Sims 4?  If so, is OneDrive running on this computer, and have you changed any settings?  This sounds like what happens when OneDrive can't or doesn't sync certain files that are within a folder it's normally syncing overall.

For the issue with Epic, some users have reported that launching Sims 4 once through the Epic launcher has made their Epic-owned packs appear in the EA App.

Let's put the Gallery issue aside for the moment.  The Gallery was down for maintenance last week, and while it's back online, functions have been restored at different points.  So it could be that the Gallery works fine for you now, or at least that it will once your other issues have been addressed.