Bukkit

They changed how the chunk queue functions in build 3022 which causes the server to crash if you have the chunks feature in nolagg enabled.

build 3022 git commit:
https://github.com/Bukkit/CraftBukkit/commit/85f5776df2a9c827565e799f150ae8a197086a98

error: (The Problem is technically in BKComLib, but will only be triggered if nolagg chunks in enabled.)
[12:01:29] [Server thread/WARN]: Failed to handle packet for 192.168.1.96/192.168.1.96:34579
java.lang.IllegalStateException: Unknown org.bukkit.craftbukkit.v1_7_R1.chunkio.QueuedChunk@9b57338e
    at org.bukkit.craftbukkit.v1_7_R1.util.AsynchronousExecutor.drop(AsynchronousExecutor.java:266) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at org.bukkit.craftbukkit.v1_7_R1.chunkio.ChunkIOExecutor.dropQueuedChunkLoad(ChunkIOExecutor.java:25) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.PlayerChunk.b(PlayerChunk.java:70) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.PlayerChunkMap.movePlayer(PlayerChunkMap.java:232) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at com.bergerkiller.bukkit.common.bases.PlayerChunkMapBase.movePlayer(PlayerChunkMapBase.java:79) ~[?:?]
    at com.bergerkiller.bukkit.nolagg.chunks.antiloader.DummyPlayerManager.movePlayer(DummyPlayerManager.java:66) ~[?:?]
    at com.bergerkiller.bukkit.common.bases.PlayerChunkMapBase.movePlayer(PlayerChunkMapBase.java:61) ~[?:?]
    at net.minecraft.server.v1_7_R1.PlayerList.d(PlayerList.java:271) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:416) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.PacketPlayInFlying.a(SourceFile:137) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.PacketPlayInPosition.handle(SourceFile:63) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:655) [craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) [craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) [craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
[12:01:29] [Server thread/INFO]: cartman2000 lost connection: Internal server error
[12:01:29] [Server thread/ERROR]: Encountered an unexpected exception
java.lang.IllegalStateException: Unknown org.bukkit.craftbukkit.v1_7_R1.chunkio.QueuedChunk@9b573122
    at org.bukkit.craftbukkit.v1_7_R1.util.AsynchronousExecutor.drop(AsynchronousExecutor.java:266) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at org.bukkit.craftbukkit.v1_7_R1.chunkio.ChunkIOExecutor.dropQueuedChunkLoad(ChunkIOExecutor.java:25) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.PlayerChunk.b(PlayerChunk.java:70) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.PlayerChunkMap.removePlayer(PlayerChunkMap.java:191) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at com.bergerkiller.bukkit.common.bases.PlayerChunkMapBase.removePlayer(PlayerChunkMapBase.java:97) ~[?:?]
    at com.bergerkiller.bukkit.common.bases.PlayerChunkMapBase.removePlayer(PlayerChunkMapBase.java:70) ~[?:?]
    at net.minecraft.server.v1_7_R1.PlayerList.disconnect(PlayerList.java:293) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:702) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:128) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:655) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) ~[craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
    at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [craftbukkit_b3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]

Confirmed, i am experiencing this too

Full server crash report http://pastebin.com/1YyJkP3v

After removing nolagg, the error was gone

You don't really need to remove the whole plugin to get rid of the crash, you just need to disable the nolagg chunks section of the plugin, as it's that that is causing the crash.

Also another temporary workaround, if you want to run with nolagg chunks enabled, would be to downgrade to CB3020 as this build is stable with nolagg chunks. As it looks like you're running the spigot server from the crash report, you would have to downgrade to a build that doesn't include the commit in CB3022 for that to work.

@cartman_2000: Go

Oh thanks! That fixed it indeed