[12:36:09] [Server thread/ERROR]: Failed to save chunk [-618474, 523030]
java.util.concurrent.CompletionException: java.lang.AbstractMethodError: Method net/minecraft/world/level/block/entity/DecoratedPotBlockEntity.getViewers()Ljava/util/List; is abstract
	at java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:315) ~[?:?]
	at java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:320) ~[?:?]
	at java.util.concurrent.CompletableFuture$UniAccept.tryFire(CompletableFuture.java:722) ~[?:?]
	at java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:482) ~[?:?]
	at net.minecraft.server.level.PlayerChunkMap.b(PlayerChunkMap.java:562) ~[spigot-1.20.3-R0.1-SNAPSHOT.jar:3956-Spigot-9d72885-5a7080b]
	at net.minecraft.server.level.PlayerChunkMap.a(PlayerChunkMap.java:531) ~[spigot-1.20.3-R0.1-SNAPSHOT.jar:3956-Spigot-9d72885-5a7080b]
	at net.minecraft.server.level.ChunkProviderServer.a(ChunkProviderServer.java:393) ~[spigot-1.20.3-R0.1-SNAPSHOT.jar:3956-Spigot-9d72885-5a7080b]
	at net.minecraft.server.level.WorldServer.a(WorldServer.java:405) ~[spigot-1.20.3-R0.1-SNAPSHOT.jar:3956-Spigot-9d72885-5a7080b]
	at net.minecraft.server.MinecraftServer.b(MinecraftServer.java:1390) ~[spigot-1.20.3-R0.1-SNAPSHOT.jar:3956-Spigot-9d72885-5a7080b]
	at net.minecraft.server.dedicated.DedicatedServer.b(DedicatedServer.java:387) ~[spigot-1.20.3-R0.1-SNAPSHOT.jar:3956-Spigot-9d72885-5a7080b]
	at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:1248) ~[spigot-1.20.3-R0.1-SNAPSHOT.jar:3956-Spigot-9d72885-5a7080b]
	at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:1054) ~[spigot-1.20.3-R0.1-SNAPSHOT.jar:3956-Spigot-9d72885-5a7080b]
	at net.minecraft.server.MinecraftServer.lambda$0(MinecraftServer.java:304) ~[spigot-1.20.3-R0.1-SNAPSHOT.jar:3956-Spigot-9d72885-5a7080b]
	at java.lang.Thread.run(Thread.java:1623) ~[?:?]
Caused by: java.lang.AbstractMethodError: Method net/minecraft/world/level/block/entity/DecoratedPotBlockEntity.getViewers()Ljava/util/List; is abstract
	at net.minecraft.world.level.block.entity.DecoratedPotBlockEntity.getViewers(SourceFile) ~[spigot-1.20.3-R0.1-SNAPSHOT.jar:3956-Spigot-9d72885-5a7080b]
	at net.minecraft.server.level.WorldServer.a(WorldServer.java:1129) ~[spigot-1.20.3-R0.1-SNAPSHOT.jar:3956-Spigot-9d72885-5a7080b]
	at net.minecraft.server.level.PlayerChunkMap.lambda$21(PlayerChunkMap.java:593) ~[spigot-1.20.3-R0.1-SNAPSHOT.jar:3956-Spigot-9d72885-5a7080b]
	at java.util.concurrent.CompletableFuture$UniAccept.tryFire(CompletableFuture.java:718) ~[?:?]
	... 11 more