Internal Exception

Internal Exception: io.netty.handler.codec.DecoderException: java.lang.IndexOutOfBoundsException: index: 5, length: 13632 (expected: range(0,30))

Open config.yml of ItemsAdder and change this value to false: optimized-packets: false

config.yml

  custom-entitites:
    enabled: true
    emotes: true
    interval-rendering-packets-ticks: 1
    optimized-packets: false