Here is my code to register entity renderers in 1.16. It doesn't work in 1.17.

@Mod.EventBusSubscriber(modid = McbbsWiki.ID, bus = Mod.EventBusSubscriber.Bus.MOD, value = Dist.CLIENT)
public class ClientSetupEvent {
    @SubscribeEvent
    public static void onClientSetUpEvent(FMLClientSetupEvent event) {
        RenderingRegistry.registerEntityRenderingHandler(EntityRegistry.entity_small_mcbbswiki_monster.get(), SmallMcbbsWikiMonsterRender::new);
        // and so on
    }
}

There isn't a class called "RenderingRegistry" in 1.17. So how can I register entity renderers?

In 1.17 you need to subscribe to EntityRenderersEvent.RegisterRenderers and then use the registerEntityRenderer method.
You'll also need to subscribe to EntityRenderersEvent.RegisterLayerDefinitions and then use the registerLayerDefinition method to register a layer.
You can find more on that here.

17 hours ago, uSkizzik said:

In 1.17 you need to subscribe to EntityRenderersEvent.RegisterRenderers and then use the registerEntityRenderer method.
You'll also need to subscribe to EntityRenderersEvent.RegisterLayerDefinitions and then use the registerLayerDefinition method to register a layer.
You can find more on that here.

Thank you!