Is this happening to anyone else? it won't let me downgrade my version anymore. When I click on my older version it says "Invalid Value for registry" so now I am stuck on 1.19

are you using mclauncher
if yes then go to mclauncher folder and click on the .appx file of the version you want
if you don't have it, you need to use an older version of mclauncher

I know that I'm using mclauncher, I already have the versions downloaded but it doesn't let me actually use them.

join the discord, it's better to ask there