The file structure was changed for the most recent update and broke players existing worlds and resource packs. They are gone. A lot of players lost years of work.
Comments 4
Seems like you can copy your resource packs from the old structure to the new one.
Take a look at this video.
https://www.youtube.com/watch?v=MHsE9vbBKeM
I re installed everything because I did not see this first. It took me a whole day because the interface was extremely lagging.
Hope this helps
How did you download the 1.21.120 update? By updating or reinstalling the game?