Thanks to Keetrainchild for bumping us up to 1.16.3.
This also means you need to freshen up your Optifine version. As normal Optifine is a little behind Mojang's official release, so we'll have to get along with the beta "preview" for now.
Grab your version here :
Edited Notes: The author has released the official version, the above link has been revised.