David Kha

Sorry, I thought it would attach one when it sent me to the bug report page from the client. 28b resolved the issue. I think this is a dup of MC-61032.

I am also seeing this bug with a very old world of mine (from 2010) that was last opened with 14w27b. I am still able to open it with 27b. I noticed some people on Reddit mentioning double stone slabs, and I used a ton of them in the part of the world I am working in now. I remember yesterday I had made some of those double stone slabs, and they looked different than ones that had been placed with earlier builds.

Minecraft Crash Report ----
// You're mean.

Time: 7/9/14 12:16 PM
Description: Exception ticking world

java.lang.IllegalArgumentException: Cannot get property bcl{name=age, clazz=class java.lang.Integer, values=[0, 1, 2, 3, 4, 5, 6, 7]} as it does not exist!
at bbw.b(SourceFile:91)
at ayt.b(SourceFile:127)
at ayt.c(SourceFile:69)
at ary.b(SourceFile:416)
at qg.h(SourceFile:373)
at qg.c(SourceFile:199)
at net.minecraft.server.MinecraftServer.x(SourceFile:578)
at net.minecraft.server.MinecraftServer.w(SourceFile:510)
at cwg.w(SourceFile:132)
at net.minecraft.server.MinecraftServer.run(SourceFile:426)
at java.lang.Thread.run(Thread.java:695)

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

– Head –
Stacktrace:
at bbw.b(SourceFile:91)
at ayt.b(SourceFile:127)
at ayt.c(SourceFile:69)
at ary.b(SourceFile:416)
at qg.h(SourceFile:373)
at qg.c(SourceFile:199)

– Affected level –
Details:
Level name: Happy Smurf Land
All players: 1 total; [qj['HappySmurfday'/72, l='Happy Smurf Land', x=162.97, y=63.50, z=-120.85]]
Chunk stats: ServerChunkCache: 1064 Drop: 0
Level seed: 109568207
Level generator: ID 00 - default, ver 1. Features enabled: true
Level generator options:
Level spawn location: -120.00,65.00,143.00 - World: (-120,65,143), Chunk: (at 8,4,15 in -8,8; contains blocks -128,0,128 to -113,255,143), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Level time: 68945162 game time, 76546536 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 18824 (now: true), thunder time: 24216 (now: false)
Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
at net.minecraft.server.MinecraftServer.x(SourceFile:578)
at net.minecraft.server.MinecraftServer.w(SourceFile:510)
at cwg.w(SourceFile:132)
at net.minecraft.server.MinecraftServer.run(SourceFile:426)
at java.lang.Thread.run(Thread.java:695)

– System Details –
Details:
Minecraft Version: 14w28a
Operating System: Mac OS X (x86_64) version 10.9.4
Java Version: 1.6.0_65, Apple Inc.
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
Memory: 60910600 bytes (58 MB) / 304644096 bytes (290 MB) up to 1069416448 bytes (1019 MB)
JVM Flags: 1 total; -Xmx1G
IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
Profiler Position: N/A (disabled)
Player Count: 1 / 8; [qj['HappySmurfday'/72, l='Happy Smurf Land', x=162.97, y=63.50, z=-120.85]]
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.

Workaround: Hold the forward button while riding in a cart.