IllegalArgumentException: Payload may not be larger than X bytes

What the log looks like

java\.lang\.IllegalArgumentException: Payload may not be larger than \d+ bytes

How to fix it

1. Install a packet-limit mod for your Minecraft version and loader—such as Packet Fixer (Forge/NeoForge/Fabric 1.18+) or XL Packets (Forge/Fabric 1.16+)—on both client and server to raise the hardcoded byte limit.
2. If the crash happens during world login on Fabric (mentioning RegistrySyncManager in the log), update Fabric API to the latest build for your Minecraft version or remove a few content-heavy mods to shrink the registry sync packet.
3. If an Applied Energistics 2 terminal is blank or crashes when withdrawing an item, pull your storage cells from the ME Drive to find the offending disk, then extract nested backpacks, graves, or NBT-heavy items using an ME IO Port or an ME Export Bus with a Fuzzy Card instead of opening the terminal.
4. Filter mob farm and quarry outputs so unstackable gear, enchanted items, and NBT containers are trashed or routed to separate chests rather than flooding digital storage cells.

Check your own log