Crash 1.8 on betacraft.fr map pvpkit

---- Minecraft Crash Report ----
// Oh - I know what I did wrong!

Time: 18/10/14 09:54
Description: Ticking entity

java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Byte
    at xv.a(SourceFile:92)
    at ws.l(SourceFile:71)
    at ws.i_(SourceFile:156)
    at ws.m(SourceFile:135)
    at abq.m(SourceFile:38)
    at abt.m(SourceFile:1007)
    at xm.s_(SourceFile:1296)
    at xn.s_(SourceFile:211)
    at abt.s_(SourceFile:1036)
    at wv.ak(SourceFile:1348)
    at xm.ak(SourceFile:1504)
    at aqu.a(SourceFile:1404)
    at aqu.g(SourceFile:1384)
    at aqu.a(SourceFile:1452)
    at aqu.g(SourceFile:1384)
    at aqu.i(SourceFile:1277)
    at bsu.r(SourceFile:1824)
    at bsu.as(SourceFile:877)
    at bsu.a(SourceFile:314)
    at net.minecraft.client.main.Main.main(SourceFile:120)


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

-- Head --
Stacktrace:
    at xv.a(SourceFile:92)
    at ws.l(SourceFile:71)
    at ws.i_(SourceFile:156)
    at ws.m(SourceFile:135)
    at abq.m(SourceFile:38)
    at abt.m(SourceFile:1007)
    at xm.s_(SourceFile:1296)
    at xn.s_(SourceFile:211)
    at abt.s_(SourceFile:1036)
    at wv.ak(SourceFile:1348)
    at xm.ak(SourceFile:1504)
    at aqu.a(SourceFile:1404)
    at aqu.g(SourceFile:1384)
    at aqu.a(SourceFile:1452)
    at aqu.g(SourceFile:1384)

-- Entity being ticked --
Details:
    Entity Type: Item (adw)
    Entity ID: 1000000331
    Entity Name: item.tile.stone.stone
    Entity's Exact location: 0,17, 174,71, -5,16
    Entity's Block location: 0,00,174,00,-6,00 - World: (0,174,-6), Chunk: (at 0,10,10 in 0,-1; contains blocks 0,0,-16 to 15,255,-1), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
    Entity's Momentum: -0,04, 0,12, 0,09
    Entity's Rider: abt['Cheval'/1000000330, l='MpServer', x=0,22, y=174,59, z=-5,25]
    Entity's Vehicle: ~~ERROR~~ NullPointerException: null
Stacktrace:
    at aqu.i(SourceFile:1277)

-- Affected level --
Details:
    Level name: MpServer
    All players: 3 total; [cio['GatsbY'/15301, l='MpServer', x=3,50, y=105,00, z=3,50], cip['Thezdrone'/1563, l='MpServer', x=-0,58, y=118,67, z=-3,24], cip['Augustin'/1576, l='MpServer', x=0,22, y=118,00, z=-5,34]]
    Chunk stats: MultiplayerChunkCache: 185, 185
    Level seed: 0
    Level generator: ID 02 - largeBiomes, ver 0. Features enabled: false
    Level generator options:
    Level spawn location: -1,00,64,00,0,00 - World: (-1,64,0), Chunk: (at 15,4,0 in -1,0; contains blocks -16,0,0 to -1,255,15), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
    Level time: 224535858 game time, 227015031 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: survival (ID 0). Hardcore: false. Cheats: false
    Forced entities: ~~ERROR~~ ClassCastException: amj cannot be cast to java.lang.String
    Retry entities: 0 total; []
    Server brand: BungeeCord (git:BungeeCord-Bootstrap:1.8-SNAPSHOT:"faf9034":1015) <- Spigot
    Server type: Non-integrated multiplayer server
Stacktrace:
    at cen.a(SourceFile:308)
    at bsu.b(SourceFile:2252)
    at bsu.a(SourceFile:323)
    at net.minecraft.client.main.Main.main(SourceFile:120)

-- System Details --
Details:
    Minecraft Version: 1.8
    Operating System: Linux (amd64) version 3.12-kali1-amd64
    Java Version: 1.7.0_55, Oracle Corporation
    Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Oracle Corporation
    Memory: 137852728 bytes (131 MB) / 438829056 bytes (418 MB) up to 954728448 bytes (910 MB)
    JVM Flags: 1 total; -Xmx1G
    IntCache: cache: 0, tcache: 64, allocated: 13, tallocated: 99
    Launched Version: 1.8
    LWJGL: 2.9.1
    OpenGL: Mesa DRI Intel(R) Sandybridge Mobile  GL version 3.0 Mesa 8.0.5, Tungsten Graphics, Inc
    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: []
    Current Language: Français (France)
    Profiler Position: N/A (disabled)