SavitarZ349

Error: java.lang.NullPointerException: Cannot invoke "org.apache.commons.lang3.tuple.Pair.getLeft()" because the return value of "java.util.Map.get(Object)" is null Exit Code: -1 Crash Report: https://paste.ee/p/Stqy1

My world won't start anymore after it crashed and I really don't want to have to restart this world i'm playing on The server console just says [Server thread/ERROR] [minecraft/Structures]: Unknown structure piece id: minecraft:bigdungeon and never starts. Here is console:

Whenever I load into my Minecraft server and open my inventory it unloads my skin and switches it to either Alex or Steve.