server crash report:

---- Minecraft Crash Report ----
// I'm sorry, Dave.

Time: 17/10/15 23:34
Description: Watching Server

java.lang.Error
at ahf.a(SourceFile:212)
at ahf.b(SourceFile:604)
at ahf.a(SourceFile:2083)
at ahf.c(SourceFile:2107)
at ahf.w(SourceFile:2052)
at arn.e(SourceFile:1081)
at arn.o(SourceFile:1014)
at arn.b(SourceFile:841)
at lp.j(SourceFile:358)
at lp.d(SourceFile:204)
at net.minecraft.server.MinecraftServer.D(SourceFile:610)
at la.D(SourceFile:314)
at net.minecraft.server.MinecraftServer.C(SourceFile:546)
at net.minecraft.server.MinecraftServer.run(SourceFile:450)
at java.lang.Thread.run(Unknown Source)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Stacktrace:
at ahf.a(SourceFile:212)
at ahf.b(SourceFile:604)
at ahf.a(SourceFile:2083)
at ahf.c(SourceFile:2107)
at ahf.w(SourceFile:2052)
at arn.e(SourceFile:1081)
at arn.o(SourceFile:1014)
at arn.b(SourceFile:841)
at lp.j(SourceFile:358)
at lp.d(SourceFile:204)
at net.minecraft.server.MinecraftServer.D(SourceFile:610)
at la.D(SourceFile:314)
at net.minecraft.server.MinecraftServer.C(SourceFile:546)

– Thread Dump –
Details:
Threads: "Netty Server IO #5" Id=33 RUNNABLE (in native)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(Native Method)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.access$400(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl.doSelect(Unknown Source)
at sun.nio.ch.SelectorImpl.lockAndDoSelect(Unknown Source)

• locked io.netty.channel.nio.SelectedSelectionKeySet@1e61eec6
• locked java.util.Collections$UnmodifiableSet@10a6137a
• locked sun.nio.ch.WindowsSelectorImpl@149985b6
  at sun.nio.ch.SelectorImpl.select(Unknown Source)
  at io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:622)
  at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:310)
  ...

"Netty Server IO #4" Id=32 RUNNABLE
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(Native Method)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.access$400(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl.doSelect(Unknown Source)
at sun.nio.ch.SelectorImpl.lockAndDoSelect(Unknown Source)

• locked io.netty.channel.nio.SelectedSelectionKeySet@519b1941
• locked java.util.Collections$UnmodifiableSet@409dca6a
• locked sun.nio.ch.WindowsSelectorImpl@60002cc0
  at sun.nio.ch.SelectorImpl.select(Unknown Source)
  at io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:622)
  at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:310)
  ...

"Netty Server IO #3" Id=31 RUNNABLE (in native)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(Native Method)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.access$400(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl.doSelect(Unknown Source)
at sun.nio.ch.SelectorImpl.lockAndDoSelect(Unknown Source)

• locked io.netty.channel.nio.SelectedSelectionKeySet@38eca143
• locked java.util.Collections$UnmodifiableSet@31b4e60e
• locked sun.nio.ch.WindowsSelectorImpl@1f54b4c8
  at sun.nio.ch.SelectorImpl.select(Unknown Source)
  at io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:622)
  at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:310)
  ...

"File IO Thread" Id=41 TIMED_WAITING
at java.lang.Thread.sleep(Native Method)
at azd.c(SourceFile:51)
at azd.run(SourceFile:30)
at java.lang.Thread.run(Unknown Source)

"Netty Server IO #2" Id=30 RUNNABLE (in native)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(Native Method)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.access$400(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl.doSelect(Unknown Source)
at sun.nio.ch.SelectorImpl.lockAndDoSelect(Unknown Source)

• locked io.netty.channel.nio.SelectedSelectionKeySet@7e53fdce
• locked java.util.Collections$UnmodifiableSet@23e8adfe
• locked sun.nio.ch.WindowsSelectorImpl@35fabb1b
  at sun.nio.ch.SelectorImpl.select(Unknown Source)
  at io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:622)
  at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:310)
  ...

"Netty Server IO #1" Id=29 RUNNABLE (in native)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(Native Method)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.access$400(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl.doSelect(Unknown Source)
at sun.nio.ch.SelectorImpl.lockAndDoSelect(Unknown Source)

• locked io.netty.channel.nio.SelectedSelectionKeySet@fb2ab98
• locked java.util.Collections$UnmodifiableSet@6eee9a2d
• locked sun.nio.ch.WindowsSelectorImpl@80f5d53
  at sun.nio.ch.SelectorImpl.select(Unknown Source)
  at io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:622)
  at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:310)
  ...

"Server Watchdog" Id=37 RUNNABLE
at sun.management.ThreadImpl.dumpThreads0(Native Method)
at sun.management.ThreadImpl.dumpAllThreads(Unknown Source)
at lb.run(SourceFile:43)
at java.lang.Thread.run(Unknown Source)

"Netty Server IO #0" Id=28 RUNNABLE (in native)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(Native Method)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.access$400(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl.doSelect(Unknown Source)
at sun.nio.ch.SelectorImpl.lockAndDoSelect(Unknown Source)

• locked io.netty.channel.nio.SelectedSelectionKeySet@684d0d2a
• locked java.util.Collections$UnmodifiableSet@723995d0
• locked sun.nio.ch.WindowsSelectorImpl@689c5648
  at sun.nio.ch.SelectorImpl.select(Unknown Source)
  at io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:622)
  at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:310)
  ...

"D3D Screen Updater" Id=26 TIMED_WAITING on java.lang.Object@1a8b6bcd
at java.lang.Object.wait(Native Method)

• waiting on java.lang.Object@1a8b6bcd
  at sun.java2d.d3d.D3DScreenUpdateManager.run(Unknown Source)
  at java.lang.Thread.run(Unknown Source)

"DestroyJavaVM" Id=25 RUNNABLE

"Server console handler" Id=23 RUNNABLE (in native)
at java.io.FileInputStream.readBytes(Native Method)
at java.io.FileInputStream.read(Unknown Source)
at java.io.BufferedInputStream.read1(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)

• locked java.io.BufferedInputStream@1a2f11eb
  at sun.nio.cs.StreamDecoder.readBytes(Unknown Source)
  at sun.nio.cs.StreamDecoder.implRead(Unknown Source)
  at sun.nio.cs.StreamDecoder.read(Unknown Source)
• locked java.io.InputStreamReader@2406806b
  at java.io.InputStreamReader.read(Unknown Source)
  ...

"Server thread" Id=22 RUNNABLE
at ahf.a(SourceFile:212)
at ahf.b(SourceFile:604)
at ahf.a(SourceFile:2083)
at ahf.c(SourceFile:2107)
at ahf.w(SourceFile:2052)
at arn.e(SourceFile:1081)
at arn.o(SourceFile:1014)
at arn.b(SourceFile:841)
...

"TimerQueue" Id=20 TIMED_WAITING on java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject@6fb66fbf
at sun.misc.Unsafe.park(Native Method)

• waiting on java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject@6fb66fbf
  at java.util.concurrent.locks.LockSupport.parkNanos(Unknown Source)
  at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(Unknown Source)
  at java.util.concurrent.DelayQueue.take(Unknown Source)
  at javax.swing.TimerQueue.run(Unknown Source)
  at java.lang.Thread.run(Unknown Source)

Number of locked synchronizers = 1

• java.util.concurrent.locks.ReentrantLock$NonfairSync@2e22bcb5

"Thread-4" Id=19 WAITING on java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject@df48beb
at sun.misc.Unsafe.park(Native Method)

• waiting on java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject@df48beb
  at java.util.concurrent.locks.LockSupport.park(Unknown Source)
  at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source)
  at java.util.concurrent.LinkedBlockingQueue.take(Unknown Source)
  at com.mojang.util.QueueLogAppender.getNextLogEvent(QueueLogAppender.java:77)
  at ld$4.run(SourceFile:119)
  at java.lang.Thread.run(Unknown Source)

"AWT-EventQueue-0" Id=18 WAITING on java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject@1de147e6
at sun.misc.Unsafe.park(Native Method)

• waiting on java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject@1de147e6
  at java.util.concurrent.locks.LockSupport.park(Unknown Source)
  at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source)
  at java.awt.EventQueue.getNextEvent(Unknown Source)
  at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
  at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
  at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
  at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
  ...

"AWT-Windows" Id=16 RUNNABLE (in native)
at sun.awt.windows.WToolkit.eventLoop(Native Method)
at sun.awt.windows.WToolkit.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

"AWT-Shutdown" Id=15 WAITING on java.lang.Object@261d87fb
at java.lang.Object.wait(Native Method)

• waiting on java.lang.Object@261d87fb
  at java.lang.Object.wait(Unknown Source)
  at sun.awt.AWTAutoShutdown.run(Unknown Source)
  at java.lang.Thread.run(Unknown Source)

"Java2D Disposer" Id=14 WAITING on java.lang.ref.ReferenceQueue$Lock@7a0acf10
at java.lang.Object.wait(Native Method)

• waiting on java.lang.ref.ReferenceQueue$Lock@7a0acf10
  at java.lang.ref.ReferenceQueue.remove(Unknown Source)
  at java.lang.ref.ReferenceQueue.remove(Unknown Source)
  at sun.java2d.Disposer.run(Unknown Source)
  at java.lang.Thread.run(Unknown Source)

"Server Infinisleeper" Id=13 TIMED_WAITING
at java.lang.Thread.sleep(Native Method)
at la$1.run(SourceFile:77)

"Snooper Timer" Id=12 TIMED_WAITING on java.util.TaskQueue@5388b869
at java.lang.Object.wait(Native Method)

• waiting on java.util.TaskQueue@5388b869
  at java.util.TimerThread.mainLoop(Unknown Source)
  at java.util.TimerThread.run(Unknown Source)

"Attach Listener" Id=5 RUNNABLE

"Signal Dispatcher" Id=4 RUNNABLE

"Finalizer" Id=3 WAITING on java.lang.ref.ReferenceQueue$Lock@44c11b89
at java.lang.Object.wait(Native Method)

• waiting on java.lang.ref.ReferenceQueue$Lock@44c11b89
  at java.lang.ref.ReferenceQueue.remove(Unknown Source)
  at java.lang.ref.ReferenceQueue.remove(Unknown Source)
  at java.lang.ref.Finalizer$FinalizerThread.run(Unknown Source)

"Reference Handler" Id=2 WAITING on java.lang.ref.Reference$Lock@ea97eb5
at java.lang.Object.wait(Native Method)

• waiting on java.lang.ref.Reference$Lock@ea97eb5
  at java.lang.Object.wait(Unknown Source)
  at java.lang.ref.Reference$ReferenceHandler.run(Unknown Source)

Stacktrace:
at lb.run(SourceFile:59)
at java.lang.Thread.run(Unknown Source)

– System Details –
Details:
Minecraft Version: 15w42a
Operating System: Windows 8.1 (amd64) version 6.3
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 371644864 bytes (354 MB) / 478150656 bytes (456 MB) up to 2102919168 bytes (2005 MB)
JVM Flags: 2 total; -Xmx2048M -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
Profiler Position: N/A (disabled)
Player Count: 2 / 20; [lr['archerking1679'/444, l='world', x=-84,39, y=74,00, z=366,61], lr['LordTimo98'/2550, l='world', x=-174,30, y=10,00, z=-111,52]]
Is Modded: Unknown (can't tell)
Type: Dedicated Server (map_server.txt)