Never ending loading on the gallery

Since a few months now, I have a problem with my gallery : whenever I try to download a lot (or whatever) I will either get a message saying that I cannot place this lot or a never ending loading screen (where I can not exit from the gallery or even save my game).

I am trying to make a save file for my game using lots from the gallery and I can't place most of them...
At this point I tried everything: deleting the game and downloading it again, clear cache, erase my mods, check if my file was on my cloud and nothing works.

The gallery is really important in my game and I am sad that I can't use it anymore because of this bug.