when using fabric and lauching the game, it says ''requires version 0.100 of fabric'' which doesn't even exist yet, also says its imcopatible with some mods

it says ''requires version 0.100 of fabric'' which doesn't even exist yet

I don't know where you got that from since 0.118.5 is released for 1.21.4 (are you confusing Fabric Loader and Fabric API?)