NoClassDefFoundError when using ModelEngine meg:setitemmodel with MythicMobs 5.13.1

Plugin version: MythicMobs Premium 5.13.1 (build 6111) Server software: UniverseSpigot (Paper fork) 26.2-ver/26.2-dev@4ca9cd5 (built 2026-08-30), API version 26.2.build.1-stable Java version: 26 Other relevant plugin: ModelEngine R4.1.1 (build 2426)

Hi, I'm getting a recurring exception when using ModelEngine's meg:setitemmodel mechanic with MythicMobs.

Example:

- meg:setitemmodel{modelid=NPC_Mineur;partid=hand_right;material=COAL} @self

It also happens with other materials such as IRON_INGOT, NETHERITE_PICKAXE and AIR.

The exception is:

java.lang.NoClassDefFoundError:
org/yaml/snakeyaml/external/biz/base64Coder/Base64Coder

The stack trace goes through:

MythicMobs Base64Util.decode
→ InventorySerialization.decodeItemStack
→ ItemVariable.deserializeFromString
→ ModelEngine SetItemModelMechanic.getItem

The error is reproducible every time the skill containing meg:setitemmodel is executed.