issue with backpack crashing game.

[thelonious112]

playing on 1.12.2 and using the cozy inside modpack. playing with multimc. placed down the backpack and then tried to pick it back up but it went in front of me and had no texture then crashed my game. everytime i try to load the world it crashes.
crash-2019-07-11_15.54.25-server.txt

java.lang.NoSuchMethodError: net.minecraft.entity.EntityLiving$SpawnPlacementType.canSpawnAt(Lnet/minecraft/world/World;Lnet/minecraft/util/math/BlockPos;)Z
    at net.minecraft.world.WorldEntitySpawner.canCreatureTypeSpawnAtLocation(WorldEntitySpawner.java:226)
    at net.minecraft.world.WorldEntitySpawner.findChunksForSpawning(WorldEntitySpawner.java:135)
    at net.minecraft.world.WorldServer.tick(WorldServer.java:203)
    at WorldServerOF.tick(WorldServerOF.java:37)
    at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:756)
    at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:668)
    at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:239)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
    at java.lang.Thread.run(Unknown Source)