I've been playing a Survival game on a server I run for me and my cousin. We finally found enough diamonds to warrant the building of a Laser system. I placed down the pipes and the moment I place the Laser, this happens:

---- Minecraft Crash Report ----
// My bad.

Time: 11/30/14 10:35 PM
Description: Ticking entity

java.lang.NoSuchMethodError: buildcraft.api.core.Position.writeData(Lio/netty/buffer/ByteBuf;)V
at buildcraft.core.LaserData.writeData(LaserData.java:88)
at buildcraft.silicon.TileLaser.writeData(TileLaser.java:280)
at buildcraft.core.network.PacketUpdate.writeData(PacketUpdate.java:54)
at buildcraft.core.utils.Utils.toPacket(Utils.java:538)
at buildcraft.core.TileBuildCraft.func_145844_m(TileBuildCraft.java:111)
at net.minecraft.entity.player.EntityPlayerMP.func_147097_b(EntityPlayerMP.java:540)
at net.minecraft.entity.player.EntityPlayerMP.func_70071_h_(EntityPlayerMP.java:276)
at net.minecraft.world.World.func_72866_a(World.java:2070)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:648)
at net.minecraft.world.World.func_72870_g(World.java:2034)
at net.minecraft.world.World.func_72939_s(World.java:1887)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:489)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:636)
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:334)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685)

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

-- Head --
Stacktrace:
at buildcraft.core.LaserData.writeData(LaserData.java:88)
at buildcraft.silicon.TileLaser.writeData(TileLaser.java:280)
at buildcraft.core.network.PacketUpdate.writeData(PacketUpdate.java:54)
at buildcraft.core.utils.Utils.toPacket(Utils.java:538)
at buildcraft.core.TileBuildCraft.func_145844_m(TileBuildCraft.java:111)
at net.minecraft.entity.player.EntityPlayerMP.func_147097_b(EntityPlayerMP.java:540)
at net.minecraft.entity.player.EntityPlayerMP.func_70071_h_(EntityPlayerMP.java:276)
at net.minecraft.world.World.func_72866_a(World.java:2070)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:648)
at net.minecraft.world.World.func_72870_g(World.java:2034)

-- Entity being ticked --
Details:
Entity Type: null (net.minecraft.entity.player.EntityPlayerMP)
Entity ID: 1178
Entity Name: PyroTornado
Entity's Exact location: -1395.23, 71.00, 2045.55
Entity's Block location: World: (-1396,71,2045), Chunk: (at 12,4,13 in -88,127; contains blocks -1408,0,2032 to -1393,255,2047), Region: (-3,3; contains chunks -96,96 to -65,127, blocks -1536,0,1536 to -1025,255,2047)
Entity's Momentum: 0.00, -0.08, 0.00
Stacktrace:
at net.minecraft.world.World.func_72939_s(World.java:1887)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:489)

-- Affected level --
Details:
Level name: Forge Server World
All players: 1 total; [EntityPlayerMP['PyroTornado'/1178, l='Forge Server World', x=-1395.23, y=71.00, z=2045.55]]
Chunk stats: ServerChunkCache: 774 Drop: 0
Level seed: 1473894354065157088
Level generator: ID 00 - default, ver 1. Features enabled: true
Level generator options:
Level spawn location: World: (132,64,256), Chunk: (at 4,4,0 in 8,16; contains blocks 128,0,256 to 143,255,271), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 5280378 game time, 5877 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 13252 (now: false), thunder time: 8094 (now: false)
Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:636)
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:334)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685)

-- System Details --
Details:
Minecraft Version: 1.7.10
Operating System: Windows 8.1 (amd64) version 6.3
Java Version: 1.7.0_60, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 385587992 bytes (367 MB) / 922222592 bytes (879 MB) up to 1398276096 bytes (1333 MB)
JVM Flags: 2 total; -Xms700M -Xmx1500M
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 96
FML: MCP v9.05 FML v7.10.85.1230 Minecraft Forge 10.13.2.1230 16 mods loaded, 16 mods active
mcp{9.05} Minecraft Coder Pack Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
FML{7.10.85.1230} Forge Mod Loader Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
Forge{10.13.2.1230} Minecraft Forge Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
Backpack{2.0.1} Backpack Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
BuildCraft|Core{6.2.1} BuildCraft Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
BuildCraft|Transport{6.2.1} BC Transport Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
BuildCraft|Silicon{6.2.1} BC Silicon Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
BuildCraft|Builders{6.2.1} BC Builders Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
BuildCraft|Energy{6.2.1} BC Energy Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
BuildCraft|Factory{6.2.1} BC Factory Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
eureka{2.1} Eureka Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
bcadditions{1.8.1} Buildcraft Additions Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
CustomSpawner{3.3.0} [DrZhark's CustomSpawner](CustomMobSpawner 3.3.0.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
MoCreatures{6.3.0} [DrZhark's Mo'Creatures Mod](DrZharks MoCreatures Mod v6.3.0.zip) Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
millenaire{6.0.0} Millénaire Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
quiverchevsky{b73} QuiverBow Unloaded->Constructed->Pre-initialized->Initialized->Post-initialized->Available->Available->Available->Available
Profiler Position: N/A (disabled)
Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Player Count: 1 / 20; [EntityPlayerMP['PyroTornado'/1178, l='Forge Server World', x=-1395.23, y=71.00, z=2045.55]]
Is Modded: Definitely; Server brand changed to 'fml,forge'
Type: Dedicated Server (map_server.txt)

I looked at the code and it seems to be looking for a class called Position, as part of the buildcraft core api, which is no longer there.

@PyroTornado The class is still there, what's happening is some mod bundling a potentially outdated BuildCraft API. Could you send me the modpack's mods/ JARs (JARs only, I'm on mobile) quickly?

@PyroTornado you are using BCA 1.8.1, that is shiping the old BC 6.1 api, fixed version will be out once i have the last textures

@asiekierka i already looked through the list