Started a creative mode game, and I spawned in a way that my feet were inside of part of a building (my feet intersected another block), and when I tried to move to get out of this glitched situation, the game crashed, and left me with this error report in the launcher.

---- Minecraft Crash Report ----
// You should try our sister game, Minceraft!

Time: 12/3/15 12:37 AM
Description: Exception ticking world

java.lang.IllegalArgumentException: Cannot get property arh

as it does not exist in aqv

at aqv$a.c(SourceFile:165)
at als.k(SourceFile:50)
at aqv$a.q(SourceFile:388)
at ahu.a(SourceFile:203)
at ahu.a(SourceFile:132)
at lp.d(SourceFile:198)
at net.minecraft.server.MinecraftServer.D(SourceFile:617)
at net.minecraft.server.MinecraftServer.C(SourceFile:553)
at bxz.C(SourceFile:154)
at net.minecraft.server.MinecraftServer.run(SourceFile:457)
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 aqv$a.c(SourceFile:165)
at als.k(SourceFile:50)
at aqv$a.q(SourceFile:388)
at ahu.a(SourceFile:203)
at ahu.a(SourceFile:132)
at lp.d(SourceFile:198)

– Affected level –
Details:
Level name: Test 15w49a
All players: 1 total; [lr['Videogamer555'/20, l='Test 15w49a', x=615.47, y=18.50, z=830.41]]
Chunk stats: ServerChunkCache: 289 Drop: 0
Level seed: 4473667976090178847
Level generator: ID 01 - flat, ver 0. Features enabled: true
Level generator options: 3;minecraft:bedrock,10*minecraft:dirt,minecraft:grass;1;village
Level spawn location: World: (623,4,833), Chunk: (at 15,0,1 in 38,52; contains blocks 608,0,832 to 623,255,847), Region: (1,1; contains chunks 32,32 to 63,63, blocks 512,0,512 to 1023,255,1023)
Level time: 74 game time, 74 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 86938 (now: false), thunder time: 176986 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
at net.minecraft.server.MinecraftServer.D(SourceFile:617)
at net.minecraft.server.MinecraftServer.C(SourceFile:553)
at bxz.C(SourceFile:154)
at net.minecraft.server.MinecraftServer.run(SourceFile:457)
at java.lang.Thread.run(Unknown Source)

– System Details –
Details:
Minecraft Version: 15w49a
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.8.0_51, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 127140024 bytes (121 MB) / 250150912 bytes (238 MB) up to 523501568 bytes (499 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Profiler Position: N/A (disabled)
Player Count: 1 / 8; [lr['Videogamer555'/20, l='Test 15w49a', x=615.47, y=18.50, z=830.41]]
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.