Silk

Even though it is only a minor version jump, this is a major minecraft update under the hood, so most mods need to be updated. Older Silk versions for 1.19 (Silk 1.9.3 and lower) do not work for 1.19.3.

Internally Mojang changed major parts of the Registry and Command System, and there a changes all over the place since Minecraft 1.19.3 already contains several 1.20 features as opt in.