I host a Minecraft server for me and my friend to play on and we want a few mods that aren’t available on fabric or even for our version so I was wondering if I could safely downgrade and change to forge without corrupting the already existing world
#Is it possible to change the version of my server from 1.21.4 to 1.20.1 and change the mod loader
hardy temple
unkempt iris
That big of a step down in version, no. There's a bunch of things on the server that were introduced way past 1.20.1 in vanilla minecraft that the server won't recognize.
Switching modloaders
completely depends on the mods, can be pretty tricky, usually only possible if all the mods are also available in the other modloaders same version.
hardy temple
So switching mod loaders in possible but not versions
unkempt iris
Switching versions down typically isnt, maybe (?) with very small steps down (like .3 to .2) but definitely not whole versions like that.