2013-10-27 16:07:32 [INFO] [STDERR] Caused by: java.lang.ClassNotFoundException: net.minecraft.world.gen.structure.ComponentMineshaftRoom
2013-10-27 16:07:32 [INFO] [STDERR] 	at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:139)
2013-10-27 16:07:32 [INFO] [STDERR] 	at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
2013-10-27 16:07:32 [INFO] [STDERR] 	at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
2013-10-27 16:07:32 [INFO] [STDERR] 	... 18 more
2013-10-27 16:07:32 [SEVERE] [Minecraft-Server] Encountered an unexpected exception ReportedException
net.minecraft.util.ReportedException: Exception preparing structure feature
	at net.minecraft.world.gen.ChunkProviderServer.func_73158_c(ChunkProviderServer.java:140)
	at net.minecraft.world.gen.ChunkProviderServer.func_73154_d(ChunkProviderServer.java:166)
	at net.minecraft.world.World.func_72964_e(World.java:528)
	at net.minecraft.world.World.func_72796_p(World.java:2853)
	at mods.mffs.common.ModularForceFieldSystem$MFFSChunkloadCallback.ticketsLoaded(ModularForceFieldSystem.java:727)
	at net.minecraftforge.common.ForgeChunkManager.loadWorld(ForgeChunkManager.java:510)
	at net.minecraftforge.common.ForgeInternalHandler.onDimensionLoad(ForgeInternalHandler.java:64)
	at net.minecraftforge.event.ASMEventHandler_1_ForgeInternalHandler_onDimensionLoad_Load.invoke(.dynamic)
	at net.minecraftforge.event.ASMEventHandler.invoke(ASMEventHandler.java:39)
	at net.minecraftforge.event.EventBus.post(EventBus.java:108)
	at net.minecraft.server.MinecraftServer.func_71247_a(MinecraftServer.java:251)
	at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:186)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:431)
	at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:573)
Caused by: java.lang.NoClassDefFoundError: net/minecraft/world/gen/structure/ComponentMineshaftRoom
	at net.minecraft.world.gen.structure.MapGenMineshaft.func_75049_b(SourceFile:29)
	at net.minecraft.world.gen.structure.MapGenStructure.func_75037_a(SourceFile:33)
	at net.minecraft.world.gen.MapGenBase.func_75036_a(SourceFile:29)
	at net.minecraft.world.gen.ChunkProviderGenerate.func_73154_d(ChunkProviderGenerate.java:332)
	at net.minecraft.world.gen.ChunkProviderServer.func_73158_c(ChunkProviderServer.java:131)
	... 13 more
Caused by: java.lang.ClassNotFoundException: net.minecraft.world.gen.structure.ComponentMineshaftRoom
	at cpw.mods.fml.relauncher.RelaunchClassLoader.findClass(RelaunchClassLoader.java:139)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
	... 18 more
2013-10-27 16:07:32 [SEVERE] [Minecraft-Server] This crash report has been saved to: /home/ftb_beta_1.1.6/./crash-reports/crash-2013-10-27_16.07.32-server.txt