Bukkit

What steps will reproduce the problem?
Simply creating and spawning a CommonEntity.

What is the expected output? What do you see instead?
Client crashes inmediately

What version of the product are you using?
v1.58

Do you have an error log of what happened?
Client crash log:

---- Minecraft Crash Report ----
// Don't be sad. I'll do better next time, I promise!

Time: 2014.08.25. 17:29
Description: Unexpected error

java.lang.NullPointerException: Unexpected error
    at bjb.a(SourceFile:514)
    at fz.a(SourceFile:97)
    at fz.a(SourceFile:15)
    at ej.a(SourceFile:174)
    at bje.e(SourceFile:212)
    at bao.p(SourceFile:1306)
    at bao.ak(SourceFile:774)
    at bao.f(SourceFile:728)
    at net.minecraft.client.main.Main.main(SourceFile:148)

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

-- Head --
Stacktrace:
    at bjb.a(SourceFile:514)
    at fz.a(SourceFile:97)
    at fz.a(SourceFile:15)
    at ej.a(SourceFile:174)
    at bje.e(SourceFile:212)

-- Affected level --
Details:
    Level name: MpServer
    All players: 1 total; [bjk['tomi35'/199, l='MpServer', x=-20,12, y=5,62, z=-15,63]]
    Chunk stats: MultiplayerChunkCache: 441, 441
    Level seed: 0
    Level generator: ID 01 - flat, ver 0. Features enabled: false
    Level generator options:
    Level spawn location: World: (-677,4,-827), Chunk: (at 11,0,5 in -43,-52; contains blocks -688,0,-832 to -673,255,-817), Region: (-2,-2; contains chunks -64,-64 to -33,-33, blocks -1024,0,-1024 to -513,255,-513)
    Level time: 52065 game time, 52065 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: 1 total; [bjk['tomi35'/199, l='MpServer', x=-20,12, y=5,62, z=-15,63]]
    Retry entities: 0 total; []
    Server brand: Spigot
    Server type: Non-integrated multiplayer server
Stacktrace:
    at bjf.a(SourceFile:289)
    at bao.b(SourceFile:1972)
    at bao.f(SourceFile:742)
    at net.minecraft.client.main.Main.main(SourceFile:148)

-- System Details --
Details:
    Minecraft Version: 1.7.10
    Operating System: Linux (amd64) version 3.13.0-34-generic
    Java Version: 1.8.0_11, Oracle Corporation
    Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
    Memory: 110733880 bytes (105 MB) / 248774656 bytes (237 MB) up to 1060372480 bytes (1011 MB)
    JVM Flags: 5 total; -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
    AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
    IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
    Launched Version: 1.7.10
    LWJGL: 2.9.1
    OpenGL: GeForce GTX 770/PCIe/SSE2 GL version 4.4.0 NVIDIA 340.32, NVIDIA Corporation
    GL Caps: Using GL 1.3 multitexturing.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Anisotropic filtering is supported and maximum anisotropy is 16.
Shaders are available because OpenGL 2.1 is supported.

    Is Modded: Probably not. Jar signature remains and client brand is untouched.
    Type: Client (map_client.txt)
    Resource Packs: []
    Current Language: English (US)
    Profiler Position: N/A (disabled)
    Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
    Anisotropic Filtering: On (16)

Please provide any additional information below.
The entity spawns, but the client crashes.