My minecraft (java edition) updated so that the snapshot version now says 20w14infinite. When I attempted to open minecraft in this snapshot version, none of my worlds appeared. They just were not listed anywhere as if they never existed. However, when I then try to load minecraft in the newest update version (1.15.2), it warns me not to play on any worlds created with the previous snapshot version because they may corrupt. How can I fix this issue?
If you want to switch back to the old snapshot, then first you have to open the launcher, then click 'Installations', then create a new one for 20w13b. This should allow you to play on your worlds created for the snapshots.