Exception "java.lang.NullPointerException at ux.a(SourceFile:401)" in game output

Started my trusty 15w36c world and all I got was this lousy t-shirt exception:

[19:54:01] [Server thread/WARN]: Unable to resolve BlockEntity for ItemInstance: minecraft:shield
java.lang.NullPointerException
	at ux.a(SourceFile:401)
	at uz.a(SourceFile:213)
	at ayk.a(SourceFile:50)
	at ll.b(SourceFile:153)
	at bvd.a(SourceFile:98)
	at bvd.j(SourceFile:130)
	at net.minecraft.server.MinecraftServer.run(SourceFile:427)
	at java.lang.Thread.run(Thread.java:745)
[19:54:01] [Server thread/INFO]: Preparing start region for level 0

Game continues flawlessly after that.

Forced crash

---- Minecraft Crash Report ----
// Who set us up the TNT?

Time: 02.09.15 20:00
Description: Manually triggered debug crash

java.lang.Throwable
	at azo.s(SourceFile:1625)
	at azo.as(SourceFile:929)
	at azo.a(SourceFile:378)
	at net.minecraft.client.main.Main.main(SourceFile:125)


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

-- Head --
Stacktrace:
	at bhu.a(SourceFile:361)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bjt['Kumasasa'/5, l='MpServer', x=767,43, y=56,00, z=-1902,23]]
	Chunk stats: MultiplayerChunkCache: 625, 625
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: 751,00,4,00,-1884,00 - World: (751,4,-1884), Chunk: (at 15,0,4 in 46,-118; contains blocks 736,0,-1888 to 751,255,-1873), Region: (1,-4; contains chunks 32,-128 to 63,-97, blocks 512,0,-2048 to 1023,255,-1537)
	Level time: 579823 game time, 3407 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
	Forced entities: 11 total; [vf['Huhn'/1, l='MpServer', x=748,63, y=56,00, z=-1948,38], bjt['Kumasasa'/5, l='MpServer', x=767,43, y=56,00, z=-1902,23], yb['Riese'/2, l='MpServer', x=754,50, y=56,00, z=-1912,19], yr['Dorfbewohner'/45954, l='MpServer', x=781,25, y=56,00, z=-1870,66], yr['Dorfbewohner'/3, l='MpServer', x=788,47, y=56,00, z=-1909,78], yr['Dorfbewohner'/4, l='MpServer', x=794,19, y=56,00, z=-1909,44], yr['Dorfbewohner'/54663, l='MpServer', x=791,50, y=56,00, z=-1903,53], xi['item.item.egg'/345250, l='MpServer', x=748,66, y=56,00, z=-1947,63], yr['Dorfbewohner'/59183, l='MpServer', x=765,50, y=56,00, z=-1903,50], yr['Dorfbewohner'/53075, l='MpServer', x=789,28, y=56,00, z=-1898,69], yr['Dorfbewohner'/55994, l='MpServer', x=766,09, y=56,00, z=-1901,91]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bhu.a(SourceFile:361)
	at azo.b(SourceFile:2375)
	at azo.a(SourceFile:387)
	at net.minecraft.client.main.Main.main(SourceFile:125)

-- System Details --
Details:
	Minecraft Version: 15w36c
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.8.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 465319992 bytes (443 MB) / 610119680 bytes (581 MB) up to 1060372480 bytes (1011 MB)
	JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 15w36c
	LWJGL: 2.9.4
	OpenGL: GeForce GTX 750 Ti/PCIe/SSE2 GL version 4.5.0 NVIDIA 355.60, NVIDIA Corporation
	GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

	Using VBOs: No
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: Les Misa+ patch.zip (incompatible)
	Current Language: Deutsch (Deutschland)
	Profiler Position: N/A (disabled)
	CPU: 4x Intel(R) Core(TM)2 Quad CPU Q8300 @ 2.50GHz

Maybe related to MC-87613