crashes upon generating the main world with structures enabled. only plugin is the generator.

config for world:

structures:
canyons: false
strongholds: true
villages: true
temples: true
mineshafts: true
newFeatures:
newCaves: false
newClayGenerator: false
newLakeGenerator: false
newDungeonGenerator: false
ores:
emeralds: true
other:
oldTreeGrowing: true
messages:

eyeOfEnderMsg: You can't use Eye of Ender in this world!

---- Minecraft Crash Report ----
// Shall we play a game?

Time: 07/09/13 10:50 PM
Description: Exception generating new chunk

java.lang.NullPointerException
at com.github.barteks2x.b173gen.reflection.WorldGenBaseRef.generate(WorldGenBaseRef.java:32)
at com.github.barteks2x.b173gen.generator.ChunkProviderGenerate.generateBlockSections(ChunkProviderGenerate.java:230)
at org.bukkit.craftbukkit.v1_6_R2.generator.CustomChunkGenerator.getOrCreateChunk(CustomChunkGenerator.java:98)
at net.minecraft.server.v1_6_R2.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:112)
at net.minecraft.server.v1_6_R2.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:84)
at net.minecraft.server.v1_6_R2.ChunkProviderServer.getOrCreateChunk(ChunkProviderServer.java:160)
at net.minecraft.server.v1_6_R2.World.getChunkAt(World.java:329)
at net.minecraft.server.v1_6_R2.World.getTypeId(World.java:254)
at org.bukkit.craftbukkit.v1_6_R2.CraftWorld.getBlockTypeIdAt(CraftWorld.java:86)
at com.github.barteks2x.b173gen.generator.ChunkProviderGenerate.canSpawn(ChunkProviderGenerate.java:740)
at com.github.barteks2x.b173gen.generator.ChunkProviderGenerate.getFixedSpawnLocation(ChunkProviderGenerate.java:752)
at net.minecraft.server.v1_6_R2.WorldServer.b(WorldServer.java:707)
at net.minecraft.server.v1_6_R2.WorldServer.a(WorldServer.java:687)
at net.minecraft.server.v1_6_R2.World.(World.java:195)
at net.minecraft.server.v1_6_R2.WorldServer.(WorldServer.java:47)
at net.minecraft.server.v1_6_R2.MinecraftServer.a(MinecraftServer.java:196)
at net.minecraft.server.v1_6_R2.DedicatedServer.init(DedicatedServer.java:164)
at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:397)
at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)

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

-- Head --
Stacktrace:
at com.github.barteks2x.b173gen.reflection.WorldGenBaseRef.generate(WorldGenBaseRef.java:32)
at com.github.barteks2x.b173gen.generator.ChunkProviderGenerate.generateBlockSections(ChunkProviderGenerate.java:230)
at org.bukkit.craftbukkit.v1_6_R2.generator.CustomChunkGenerator.getOrCreateChunk(CustomChunkGenerator.java:98)

-- Chunk to be generated --
Details:
Location: 0,0
Position hash: 2147483648
Generator: CustomChunkGenerator
Stacktrace:
at net.minecraft.server.v1_6_R2.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:112)
at net.minecraft.server.v1_6_R2.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:84)
at net.minecraft.server.v1_6_R2.ChunkProviderServer.getOrCreateChunk(ChunkProviderServer.java:160)
at net.minecraft.server.v1_6_R2.World.getChunkAt(World.java:329)

-- Requested block coordinates --
Details:
Found chunk: true
Location: World: (0,64,0), Chunk: (at 0,4,0 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Stacktrace:
at net.minecraft.server.v1_6_R2.World.getTypeId(World.java:254)
at org.bukkit.craftbukkit.v1_6_R2.CraftWorld.getBlockTypeIdAt(CraftWorld.java:86)
at com.github.barteks2x.b173gen.generator.ChunkProviderGenerate.canSpawn(ChunkProviderGenerate.java:740)
at com.github.barteks2x.b173gen.generator.ChunkProviderGenerate.getFixedSpawnLocation(ChunkProviderGenerate.java:752)
at net.minecraft.server.v1_6_R2.WorldServer.b(WorldServer.java:707)
at net.minecraft.server.v1_6_R2.WorldServer.a(WorldServer.java:687)

-- Affected level --
Details:
Level name: overworld
All players: 0 total; []
Chunk stats: ServerChunkCache: 0 Drop: 0
Level seed: -7718820916878340431
Level generator: ID 00 - default, ver 1. Features enabled: true
Level generator options:
Level spawn location: World: (0,0,0), Chunk: (at 0,0,0 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 0 game time, 0 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
Stacktrace:
at net.minecraft.server.v1_6_R2.World.(World.java:195)
at net.minecraft.server.v1_6_R2.WorldServer.(WorldServer.java:47)
at net.minecraft.server.v1_6_R2.MinecraftServer.a(MinecraftServer.java:196)
at net.minecraft.server.v1_6_R2.DedicatedServer.init(DedicatedServer.java:164)
at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:397)
at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)

-- System Details --
Details:
Minecraft Version: 1.6.2
Operating System: Linux (amd64) version 3.5.0-39-generic
Java Version: 1.6.0_27, Sun Microsystems Inc.
Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Sun Microsystems Inc.
Memory: 889184760 bytes (847 MB) / 1029046272 bytes (981 MB) up to 1029046272 bytes (981 MB)
JVM Flags: 2 total; -Xms1024M -Xmx1024M
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Suspicious classes: $Proxy3, ObjectMatcher, $Proxy5, ...[com.avaje.ebean.config.dbplatform.DatabasePlatform, SQLitePlatform], [gnu.trove.TByteCollection, TShortCollection, TLongCollection, ...], [gnu.trove.impl.HashFunctions, PrimeFinder, Constants], [gnu.trove.impl.hash.THash, TPrimitiveHash, TByteHash, ...], [gnu.trove.iterator.TIterator, TByteIterator, TAdvancingIterator, ...], [gnu.trove.map.TLongShortMap, TObjectIntMap], [gnu.trove.map.hash.TLongShortHashMap, TObjectIntHashMap], [gnu.trove.procedure.TLongShortProcedure, TObjectIntProcedure], [gnu.trove.set.TByteSet, TLongSet], [gnu.trove.set.hash.TByteHashSet], [io.netty.bootstrap.AbstractBootstrap, ServerBootstrap, ChannelFactory, ...], [io.netty.buffer.ByteBufAllocator, AbstractByteBufAllocator, UnpooledByteBufAllocator, ...], [io.netty.channel.EventLoopGroup, ChannelHandler, MultithreadEventLoopGroup, ...], [io.netty.channel.nio.NioEventLoopGroup, NioEventLoop, SelectedSelectionKeySet, ...], [io.netty.channel.socket.ServerSocketChannel, ServerSocketChannelConfig, DefaultServerSocketChannelConfig], [io.netty.channel.socket.nio.NioServerSocketChannel], [io.netty.util.Signal, CharsetUtil, UniqueName, ...], [io.netty.util.concurrent.EventExecutorGroup, AbstractEventExecutorGroup, MultithreadEventExecutorGroup, ...], [io.netty.util.internal.SystemPropertyUtil, PlatformDependent, PlatformDependent0, ...], [io.netty.util.internal.logging.InternalLoggerFactory, Slf4JLoggerFactory, Log4JLoggerFactory, ...], [javassist.ClassPath, ClassPool, NotFoundException, ...], [javassist.bytecode.AttributeInfo, InnerClassesAttribute, SignatureAttribute, ...], [javassist.bytecode.stackmap.TypeTag, Tracer, MapMaker, ...], [javassist.compiler.CompileError, Javac, TokenId, ...], [javassist.compiler.ast.Visitor, ASTree, ASTList, ...], [net.minecraft.server.v1_6_R2.ICommandListener, IMojangStatistics, ICommandHandler, ...], [org.bukkit.BlockChangeDelegate, World, Server, ...], [org.bukkit.block.BlockState, BlockFace, Block, ...], [org.bukkit.command.CommandSender, RemoteConsoleCommandSender, CommandException, ...], [org.bukkit.command.defaults.VanillaCommand, SaveCommand, SaveOnCommand, ...], [org.bukkit.configuration.ConfigurationSection, Configuration, MemorySection, ...], [org.bukkit.configuration.file.FileConfiguration, YamlConfiguration, FileConfigurationOptions, ...], [org.bukkit.configuration.serialization.ConfigurationSerializable, ConfigurationSerialization, DelegateDeserialization, ...], [org.bukkit.conversations.Conversable, ConversationCanceller], [org.bukkit.craftbukkit.Main], [org.bukkit.craftbukkit.libs.com.google.gson.JsonDeserializer, JsonParseException], [org.bukkit.craftbukkit.libs.jline.TerminalFactory, Terminal, Flavor, ...], [org.bukkit.craftbukkit.libs.jline.console.ConsoleReader, CursorBuffer, ConsoleKeys, ...], [org.bukkit.craftbukkit.libs.jline.console.completer.CompletionHandler, CandidateListCompletionHandler, Completer], [org.bukkit.craftbukkit.libs.jline.console.history.History, MemoryHistory], [org.bukkit.craftbukkit.libs.jline.internal.InputStreamReader, Configuration, Log, ...], [org.bukkit.craftbukkit.v1_6_R2.LoggerOutputStream, CraftServer, CraftOfflinePlayer, ...], [org.bukkit.craftbukkit.v1_6_R2.command.ServerCommandSender, CraftConsoleCommandSender, ColouredConsoleSender, ...], [org.bukkit.craftbukkit.v1_6_R2.conversations.ConversationTracker], [org.bukkit.craftbukkit.v1_6_R2.enchantments.CraftEnchantment], [org.bukkit.craftbukkit.v1_6_R2.generator.InternalChunkGenerator, CustomChunkGenerator, NormalChunkGenerator, ...], [org.bukkit.craftbukkit.v1_6_R2.help.SimpleHelpMap, CommandAliasHelpTopic, HelpYamlReader, ...], [org.bukkit.craftbukkit.v1_6_R2.inventory.CraftItemStack, CraftRecipe, CraftShapedRecipe, ...], [org.bukkit.craftbukkit.v1_6_R2.metadata.EntityMetadataStore, PlayerMetadataStore, WorldMetadataStore, ...], [org.bukkit.craftbukkit.v1_6_R2.potion.CraftPotionEffectType, CraftPotionBrewer], [org.bukkit.craftbukkit.v1_6_R2.scheduler.CraftScheduler, CraftAsyncDebugger, CraftTask, ...], [org.bukkit.craftbukkit.v1_6_R2.updater.AutoUpdater, BukkitDLUpdaterService, DateDeserializer], [org.bukkit.craftbukkit.v1_6_R2.util.ServerShutdownThread, Waitable, TerminalConsoleHandler, ...], [org.bukkit.enchantments.Enchantment, EnchantmentWrapper], [org.bukkit.entity.Entity, Damageable, LivingEntity, ...], [org.bukkit.event.Event, Cancellable, Listener, ...], [org.bukkit.event.block.BlockEvent, BlockFadeEvent, BlockGrowEvent, ...], [org.bukkit.event.entity.EntityEvent, EntityInteractEvent, EntityDamageEvent, ...], [org.bukkit.event.hanging.HangingEvent, HangingPlaceEvent], [org.bukkit.event.inventory.InventoryMoveItemEvent], [org.bukkit.event.painting.PaintingEvent, PaintingPlaceEvent], [org.bukkit.event.player.PlayerEvent, PlayerFishEvent, PlayerItemDamageEvent, ...], [org.bukkit.event.server.ServerEvent, MapInitializeEvent, ServerCommandEvent, ...], [org.bukkit.event.weather.WeatherEvent, ThunderChangeEvent, WeatherChangeEvent, ...], [org.bukkit.event.world.WorldEvent, WorldInitEvent, WorldSaveEvent, ...], [org.bukkit.generator.ChunkGenerator, BlockPopulator, BiomeGrid], [org.bukkit.help.HelpMap, HelpTopic, IndexHelpTopic, ...], [org.bukkit.inventory.ItemStack, Inventory, Recipe, ...], [org.bukkit.inventory.meta.ItemMeta, Repairable, BookMeta, ...], [org.bukkit.map.MapView], [org.bukkit.material.MaterialData, Tree, Directional, ...], [org.bukkit.metadata.Metadatable, MetadataStore, MetadataStoreBase, ...], [org.bukkit.permissions.ServerOperator, Permissible, PermissibleBase, ...], [org.bukkit.plugin.ServicesManager, PluginManager, SimpleServicesManager, ...], [org.bukkit.plugin.java.JavaPluginLoader, PluginClassLoader, JavaPlugin], [org.bukkit.plugin.messaging.PluginMessageRecipient, Messenger, StandardMessenger, ...], [org.bukkit.potion.PotionEffectType, PotionEffectTypeWrapper, PotionBrewer, ...], [org.bukkit.scheduler.BukkitScheduler, BukkitTask], [org.bukkit.scoreboard.ScoreboardManager, DisplaySlot], [org.bukkit.util.Vector, BlockVector, Java15Compat, ...], [org.fusesource.jansi.AnsiOutputStream, Ansi, NoAnsi, ...], [org.spigotmc.SpigotConfig, Listener, LogFilter, ...], [org.spigotmc.netty.NettyServerConnection], [org.yaml.snakeyaml.DumperOptions, ScalarStyle, FlowStyle, ...], [org.yaml.snakeyaml.composer.Composer, ComposerException], [org.yaml.snakeyaml.constructor.BaseConstructor, SafeConstructor, Constructor, ...], [org.yaml.snakeyaml.emitter.Emitable, Emitter, EmitterException, ...], [org.yaml.snakeyaml.error.YAMLException, MarkedYAMLException, Mark], [org.yaml.snakeyaml.events.Event, NodeEvent, ScalarEvent, ...], [org.yaml.snakeyaml.external.com.google.gdata.util.common.base.Escaper, UnicodeEscaper, PercentEscaper], [org.yaml.snakeyaml.introspector.PropertyUtils, Property, MissingProperty, ...], [org.yaml.snakeyaml.nodes.Node, CollectionNode, MappingNode, ...], [org.yaml.snakeyaml.parser.Parser, ParserImpl, ParserException, ...], [org.yaml.snakeyaml.reader.UnicodeReader, StreamReader, ReaderException], [org.yaml.snakeyaml.representer.BaseRepresenter, SafeRepresenter, Representer, ...], [org.yaml.snakeyaml.resolver.Resolver, ResolverTuple], [org.yaml.snakeyaml.scanner.Scanner, ScannerImpl, ScannerException, ...], [org.yaml.snakeyaml.serializer.Serializer, SerializerException], [org.yaml.snakeyaml.tokens.Token, AliasToken, ScalarToken, ...], [org.yaml.snakeyaml.util.UriEncoder, ArrayStack]
IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63
CraftBukkit Information:
Running: CraftBukkit version git-Spigot-1091 (MC: 1.6.2) (Implementing API version 1.6.2-R0.2-SNAPSHOT) true
Plugins: { 173generator v2.1-13-g12db7e0 com.github.barteks2x.b173gen.Generator [Barteks2x], Multiverse-Core v2.5-b641 com.onarandombox.MultiverseCore.MultiverseCore [Rigby, fernferret, lithium3141, main--],}
Warnings: DEFAULT
Threads: { RUNNABLE Server thread: [java.lang.Thread.dumpThreads(Native Method), java.lang.Thread.getAllStackTraces(Thread.java:1546), org.bukkit.craftbukkit.v1_6_R2.CraftCrashReport.call(CraftCrashReport.java:28), net.minecraft.server.v1_6_R2.CrashReportSystemDetails.a(SourceFile:74), net.minecraft.server.v1_6_R2.CrashReport.h(CrashReport.java:41), net.minecraft.server.v1_6_R2.CrashReport.(CrashReport.java:28), net.minecraft.server.v1_6_R2.CrashReport.a(CrashReport.java:212), net.minecraft.server.v1_6_R2.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:114), net.minecraft.server.v1_6_R2.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:84), net.minecraft.server.v1_6_R2.ChunkProviderServer.getOrCreateChunk(ChunkProviderServer.java:160), net.minecraft.server.v1_6_R2.World.getChunkAt(World.java:329), net.minecraft.server.v1_6_R2.World.getTypeId(World.java:254), org.bukkit.craftbukkit.v1_6_R2.CraftWorld.getBlockTypeIdAt(CraftWorld.java:86), com.github.barteks2x.b173gen.generator.ChunkProviderGenerate.canSpawn(ChunkProviderGenerate.java:740), com.github.barteks2x.b173gen.generator.ChunkProviderGenerate.getFixedSpawnLocation(ChunkProviderGenerate.java:752), net.minecraft.server.v1_6_R2.WorldServer.b(WorldServer.java:707), net.minecraft.server.v1_6_R2.WorldServer.a(WorldServer.java:687), net.minecraft.server.v1_6_R2.World.(World.java:195), net.minecraft.server.v1_6_R2.WorldServer.(WorldServer.java:47), net.minecraft.server.v1_6_R2.MinecraftServer.a(MinecraftServer.java:196), net.minecraft.server.v1_6_R2.DedicatedServer.init(DedicatedServer.java:164), net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:397), net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)], TIMED_WAITING Spigot Metrics Thread: [java.lang.Object.wait(Native Method), java.util.TimerThread.mainLoop(Timer.java:531), java.util.TimerThread.run(Timer.java:484)], RUNNABLE Signal Dispatcher: [], RUNNABLE DestroyJavaVM: [], RUNNABLE Netty IO Thread - 0: [sun.nio.ch.EPollArrayWrapper.epollWait(Native Method), sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:228), sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:83), sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:87), sun.nio.ch.SelectorImpl.select(SelectorImpl.java:98), io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:635), io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:319), io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:101), java.lang.Thread.run(Thread.java:679)], WAITING Reference Handler: [java.lang.Object.wait(Native Method), java.lang.Object.wait(Object.java:502), java.lang.ref.Reference$ReferenceHandler.run(Reference.java:133)], RUNNABLE Command Reader: [java.io.FileInputStream.readBytes(Native Method), java.io.FileInputStream.read(FileInputStream.java:236), java.io.BufferedInputStream.fill(BufferedInputStream.java:235), java.io.BufferedInputStream.read(BufferedInputStream.java:254), java.io.FilterInputStream.read(FilterInputStream.java:83), org.bukkit.craftbukkit.libs.jline.console.ConsoleReader$1.read(ConsoleReader.java:167), org.bukkit.craftbukkit.libs.jline.internal.InputStreamReader.read(InputStreamReader.java:267), org.bukkit.craftbukkit.libs.jline.internal.InputStreamReader.read(InputStreamReader.java:204), org.bukkit.craftbukkit.libs.jline.console.ConsoleReader.readCharacter(ConsoleReader.java:995), org.bukkit.craftbukkit.libs.jline.console.ConsoleReader.readLine(ConsoleReader.java:1167), net.minecraft.server.v1_6_R2.ThreadCommandReader.run(ThreadCommandReader.java:32)], TIMED_WAITING Spigot Watchdog Thread: [java.lang.Thread.sleep(Native Method), org.spigotmc.WatchdogThread.run(WatchdogThread.java:86)], WAITING Finalizer: [java.lang.Object.wait(Native Method), java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:133), java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:149), java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:189)], WAITING Snooper Timer: [java.lang.Object.wait(Native Method), java.lang.Object.wait(Object.java:502), java.util.TimerThread.mainLoop(Timer.java:505), java.util.TimerThread.run(Timer.java:484)],}
Recent tasks from -31--1{}
Profiler Position: N/A (disabled)
Player Count: 0 / 20; []
Is Modded: Definitely; Server brand changed to 'craftbukkit'
Type: Dedicated Server (map_server.txt)