Failed to encode packet 'clientbound/minecraft:update_recipes' (Empty ItemStack not allowed)

What it looks like in the log

io.netty.handler.codec.EncoderException: Empty ItemStack not allowed

How to fix it

1. Open your client or server latest.log and search above the EncoderException for 'Couldn't load tag' or recipe errors to identify which mod, datapack, or plugin registered a broken tag or recipe.
2. On modded installations (NeoForge, Forge, Fabric, or Quilt), install the 'Load My F***ing Tags' (LMFT) mod to stop a single broken mod tag entry from emptying entire item tags used by recipes.
3. If you use KubeJS or custom datapacks, inspect your custom recipes for minecraft:air ingredients, empty outputs, or tags referencing removed mods, and update conflicting mods (for example, outdated Hazen 'N Stuff builds alongside Create).
4. On Paper, Folia, or Spigot 1.20.5+ servers, update plugins that add custom crafts; if you are developing the plugin, use a space character (' ') in shaped recipe patterns instead of binding an ingredient key to Material.AIR.

Check your own log