I have tried to remove the mods that it says it might be and it didn't work but when I removed Natura it stopped crashing, don't know what is causing it.

Here is the crash-log:

http://openeye.openmods.info/crashes/7f61350f2576bff0fb9b09c778d823e6

(Hope this is the right mod that is causing it)

does crash happen with railcraft 9.7.0.0? Railcraft's author has released several updates to the mod over the last six months or so. Also, check if using most recent natura.

Hi! I have a similar crash on our server with 2.2.0.1 -

[FML]: Exception caught during firing event cpw.mods.fml.common.gameevent.TickEvent$ServerTickEvent@1d1622f1:
net.minecraft.util.ReportedException: Exception getting block type in world
at net.minecraft.world.World.func_147439_a(World.java:354) ~[ahb.class:?]
at net.minecraft.world.World.func_147437_c(World.java:365) ~[ahb.class:?]
at mods.natura.worldgen.BaseCropWorldgen.generateBluebells(BaseCropWorldgen.java:179) ~[BaseCropWorldgen.class:?]
at mods.natura.worldgen.BaseCropWorldgen.generate(BaseCropWorldgen.java:60) ~[BaseCropWorldgen.class:?]
at cpw.mods.fml.common.registry.GameRegistry.generateWorld(GameRegistry.java:112) ~[GameRegistry.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73153_a(ChunkProviderServer.java:280) ~[ms.class:?]
at net.minecraft.world.chunk.Chunk.func_76624_a(Chunk.java:1050) ~[apx.class:?]
at net.minecraft.world.gen.ChunkProviderServer.originalLoadChunk(ChunkProviderServer.java:190) ~[ms.class:?]
at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:131) ~[ms.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73158_c(ChunkProviderServer.java:101) ~[ms.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73154_d(ChunkProviderServer.java:199) ~[ms.class:?]
at net.minecraft.world.World.func_72964_e(World.java:419) ~[ahb.class:?]
at net.shadowmage.ancientwarfare.structure.town.TownPlacementValidator.isAverageHeightWithin(TownPlacementValidator.java:186) ~[TownPlacementValidator.class:?]
at net.shadowmage.ancientwarfare.structure.town.TownPlacementValidator.tryExpandZPos(TownPlacementValidator.java:177) ~[TownPlacementValidator.class:?]
at net.shadowmage.ancientwarfare.structure.town.TownPlacementValidator.expandBoundingArea(TownPlacementValidator.java:134) ~[TownPlacementValidator.class:?]
at net.shadowmage.ancientwarfare.structure.town.TownPlacementValidator.findGenerationPosition(TownPlacementValidator.java:62) ~[TownPlacementValidator.class:?]
at net.shadowmage.ancientwarfare.structure.town.WorldTownGenerator.attemptGeneration(WorldTownGenerator.java:38) ~[WorldTownGenerator.class:?]
at net.shadowmage.ancientwarfare.structure.world_gen.WorldGenTickHandler.genTowns(WorldGenTickHandler.java:80) ~[WorldGenTickHandler.class:?]
at net.shadowmage.ancientwarfare.structure.world_gen.WorldGenTickHandler.serverTick(WorldGenTickHandler.java:50) ~[WorldGenTickHandler.class:?]
at cpw.mods.fml.common.eventhandler.ASMEventHandler_105_WorldGenTickHandler_serverTick_ServerTickEvent.invoke(.dynamic) ~[?:?]
at cpw.mods.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:54) ~[ASMEventHandler.class:?]
at cpw.mods.fml.common.eventhandler.EventBus.post(EventBus.java:138) [EventBus.class:?]
at cpw.mods.fml.common.FMLCommonHandler.onPostServerTick(FMLCommonHandler.java:247) [FMLCommonHandler.class:?]
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:590) [MinecraftServer.class:?]
at fastcraft.K.a(F:21) [fastcraft-1.22-ctest14.jar:?]
at fastcraft.H.aq(F:157) [fastcraft-1.22-ctest14.jar:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:396) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685) [li.class:?]
Caused by: java.lang.IllegalArgumentException
at net.minecraft.util.WeightedRandom.func_76273_a(WeightedRandom.java:28) ~[qv.class:?]
at net.minecraft.util.WeightedRandom.func_76271_a(WeightedRandom.java:60) ~[qv.class:?]
at net.minecraft.world.SpawnerAnimals.func_77191_a(SpawnerAnimals.java:235) ~[aho.class:?]
at net.minecraft.world.gen.ChunkProviderGenerate.func_73153_a(ChunkProviderGenerate.java:424) ~[aqz.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73153_a(ChunkProviderServer.java:279) ~[ms.class:?]
at net.minecraft.world.chunk.Chunk.func_76624_a(Chunk.java:1045) ~[apx.class:?]
at net.minecraftforge.common.chunkio.ChunkIOProvider.callStage2(ChunkIOProvider.java:52) ~[ChunkIOProvider.class:?]
at net.minecraftforge.common.chunkio.ChunkIOProvider.callStage2(ChunkIOProvider.java:12) ~[ChunkIOProvider.class:?]
at net.minecraftforge.common.util.AsynchronousExecutor.skipQueue(AsynchronousExecutor.java:344) ~[AsynchronousExecutor.class:?]
at net.minecraftforge.common.util.AsynchronousExecutor.getSkipQueue(AsynchronousExecutor.java:302) ~[AsynchronousExecutor.class:?]
at net.minecraftforge.common.chunkio.ChunkIOExecutor.syncChunkLoad(ChunkIOExecutor.java:12) ~[ChunkIOExecutor.class:?]
at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:126) ~[ms.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73158_c(ChunkProviderServer.java:101) ~[ms.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73154_d(ChunkProviderServer.java:199) ~[ms.class:?]
at net.minecraft.world.World.func_72964_e(World.java:419) ~[ahb.class:?]
at net.minecraft.world.World.func_147439_a(World.java:345) ~[ahb.class:?]
... 27 more
[21:39:37] [Server thread/ERROR] [FML]: Index: 4 Listeners:
[21:39:37] [Server thread/ERROR] [FML]: 0: NORMAL
[21:39:37] [Server thread/ERROR] [FML]: 1: ASM: am2.proxy.tick.ServerTickHandler@3526df55 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 2: ASM: ic2.core.TickHandler@6d6b7b6 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 3: ASM: net.shadowmage.ancientwarfare.automation.gamedata.MailboxTicker@58fdcc65 serverTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 4: ASM: net.shadowmage.ancientwarfare.structure.world_gen.WorldGenTickHandler@4ecad287 serverTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 5: ASM: us.ichun.mods.ichunutil.common.core.TickHandlerServer@c309360 serverTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 6: ASM: chylex.hee.mechanics.charms.handler.CharmPouchHandler@795bcbc1 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 7: ASM: chylex.hee.mechanics.misc.TempleEvents@3baee147 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 8: ASM: com.brandon3055.brandonscore.common.handlers.ProcessHandler@12cd8cca onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 9: ASM: mods.railcraft.client.sounds.SoundLimiterTicker@7c41f2b0 tick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 10: ASM: de.npe.gameanalytics.minecraft.ActivityReportTickEventHandler@7b55a11f serverTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 11: ASM: crazypants.enderio.machine.spawner.BlockPoweredSpawner@35f97949 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 12: ASM: crazypants.enderio.conduit.ConduitNetworkTickHandler@5334889e onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 13: ASM: net.dries007.holoInventory.util.Metrics@e24a830 tick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 14: ASM: hardcorequesting.EventHandler@2f8bc375 onEvent(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 15: ASM: hardcorequesting.quests.QuestTicker@6c71bd1 tick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 16: ASM: com.emoniph.witchery.common.ServerTickEvents@22de040b onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 17: ASM: buildcraft.core.tablet.manager.TabletManagerServer@f22141a serverTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 18: ASM: aroma1997.backup.EventListener@60eb3ace tick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 19: ASM: GridTickHandler[Energy]@1013458644 tick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 20: ASM: GridTickHandler[Redstone]@2019779209 tick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 21: ASM: GridTickHandler[Fluid]@366617874 tick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 22: ASM: powercrystals.minefactoryreloaded.net.ConnectionHandler@823e30b tick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 23: ASM: dan200.computercraft.shared.proxy.ComputerCraftProxyCommon$ForgeHandlers@27281a27 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 24: ASM: li.cil.oc.common.EventHandler$@34a62c53 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)Ljava/lang/Object;
[21:39:37] [Server thread/ERROR] [FML]: 25: ASM: li.cil.oc.common.asm.SimpleComponentTickHandler@79e539c0 onTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 26: ASM: li.cil.oc.common.item.Tablet$@6250bcb8 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 27: ASM: build.EventHandlerFML@1b949230 tickServer(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 28: ASM: CoroPets.EventHandlerFML@44967e35 tickServer(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 29: ASM: CoroUtil.forge.EventHandlerFML@1d727136 tickServer(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 30: ASM: com.enderio.core.common.util.Scheduler@253b98c3 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 31: ASM: Network Registry:
[] onTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 32: ASM: crazypants.enderio.CommonProxy$TickTimer@5cfdf26a onTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 33: ASM: thaumic.tinkerer.common.potion.PotionEffectHandler@3bd78533 onTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 34: ASM: HxCKDMS.HxCCore.Events.EventNickSync@47d1c18d onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 35: ASM: HxCKDMS.HxCCore.Events.EventTpRequest@42920be5 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 36: ASM: INSTANCE tickServer(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 37: ASM: openblocks.common.ServerTickHandler@6aba76b0 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 38: ASM: mcjty.rftools.dimension.DimensionTickEvent@25ae0e95 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 39: ASM: cofh.thermaldynamics.core.TickHandler@5ed11f81 onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 40: ASM: torched.common.core.TickHandlerServer@186652ec onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 41: ASM: codechicken.multipart.handler.MultipartEventHandler$@445c9a5e serverTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 42: ASM: com.rwtema.extrautils.CommandTPSTimer@322be71a onServerTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 43: ASM: com.forgeessentials.core.misc.TaskRegistry@1eb96c98 onTick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 44: ASM: com.forgeessentials.core.misc.TeleportHelper@3a3fad9 serverTickEvent(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 45: ASM: com.forgeessentials.util.questioner.Questioner@5a5a2465 tickStart(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 46: ASM: com.forgeessentials.multiworld.MultiworldManager@5e4c80f5 serverTickEvent(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 47: ASM: com.forgeessentials.worldborder.ModuleWorldBorder@5b7a9237 serverTickEvent(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 48: ASM: com.forgeessentials.permissions.core.ZonedPermissionHelper@1cc10ec9 serverTickEvent(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 49: ASM: com.forgeessentials.permissions.core.PermissionScheduler@25e1e1a1 serverTickEvent(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 50: ASM: com.forgeessentials.protection.ProtectionEventHandler@5b2994bd serverTickEvent(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 51: ASM: riskyken.armourersWorkshop.common.skin.SkinDataCache@484d885a onServerTickEvent(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 52: ASM: com.forgeessentials.core.mcstats.Metrics@44ca4e8b tick(Lcpw/mods/fml/common/gameevent/TickEvent$ServerTickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 53: ASM: vazkii.botania.common.block.BlockPistonRelay@2120ff7e tickEnd(Lcpw/mods/fml/common/gameevent/TickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 54: ASM: org.dave.CompactMachines.handler.CMTickHandler@755edd07 tick(Lcpw/mods/fml/common/gameevent/TickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 55: ASM: lumien.randomthings.Handler.RTTickHandler@46adcfbd tick(Lcpw/mods/fml/common/gameevent/TickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 56: ASM: remoteio.common.tracker.BlockTracker@7de52e58 onWorldTick(Lcpw/mods/fml/common/gameevent/TickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 57: ASM: ivorius.yegamolchattels.events.YGCFMLEventHandler@57d85508 onTick(Lcpw/mods/fml/common/gameevent/TickEvent;)V
[21:39:37] [Server thread/ERROR] [FML]: 58: ASM: appeng.hooks.TickHandler@61f8ecc4 onTick(Lcpw/mods/fml/common/gameevent/TickEvent;)V
[21:39:37] [Server thread/ERROR]: Encountered an unexpected exception
net.minecraft.util.ReportedException: Exception getting block type in world
at net.minecraft.world.World.func_147439_a(World.java:354) ~[ahb.class:?]
at net.minecraft.world.World.func_147437_c(World.java:365) ~[ahb.class:?]
at mods.natura.worldgen.BaseCropWorldgen.generateBluebells(BaseCropWorldgen.java:179) ~[BaseCropWorldgen.class:?]
at mods.natura.worldgen.BaseCropWorldgen.generate(BaseCropWorldgen.java:60) ~[BaseCropWorldgen.class:?]
at cpw.mods.fml.common.registry.GameRegistry.generateWorld(GameRegistry.java:112) ~[GameRegistry.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73153_a(ChunkProviderServer.java:280) ~[ms.class:?]
at net.minecraft.world.chunk.Chunk.func_76624_a(Chunk.java:1050) ~[apx.class:?]
at net.minecraft.world.gen.ChunkProviderServer.originalLoadChunk(ChunkProviderServer.java:190) ~[ms.class:?]
at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:131) ~[ms.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73158_c(ChunkProviderServer.java:101) ~[ms.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73154_d(ChunkProviderServer.java:199) ~[ms.class:?]
at net.minecraft.world.World.func_72964_e(World.java:419) ~[ahb.class:?]
at net.shadowmage.ancientwarfare.structure.town.TownPlacementValidator.isAverageHeightWithin(TownPlacementValidator.java:186) ~[TownPlacementValidator.class:?]
at net.shadowmage.ancientwarfare.structure.town.TownPlacementValidator.tryExpandZPos(TownPlacementValidator.java:177) ~[TownPlacementValidator.class:?]
at net.shadowmage.ancientwarfare.structure.town.TownPlacementValidator.expandBoundingArea(TownPlacementValidator.java:134) ~[TownPlacementValidator.class:?]
at net.shadowmage.ancientwarfare.structure.town.TownPlacementValidator.findGenerationPosition(TownPlacementValidator.java:62) ~[TownPlacementValidator.class:?]
at net.shadowmage.ancientwarfare.structure.town.WorldTownGenerator.attemptGeneration(WorldTownGenerator.java:38) ~[WorldTownGenerator.class:?]
at net.shadowmage.ancientwarfare.structure.world_gen.WorldGenTickHandler.genTowns(WorldGenTickHandler.java:80) ~[WorldGenTickHandler.class:?]
at net.shadowmage.ancientwarfare.structure.world_gen.WorldGenTickHandler.serverTick(WorldGenTickHandler.java:50) ~[WorldGenTickHandler.class:?]
at cpw.mods.fml.common.eventhandler.ASMEventHandler_105_WorldGenTickHandler_serverTick_ServerTickEvent.invoke(.dynamic) ~[?:?]
at cpw.mods.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:54) ~[ASMEventHandler.class:?]
at cpw.mods.fml.common.eventhandler.EventBus.post(EventBus.java:138) ~[EventBus.class:?]
at cpw.mods.fml.common.FMLCommonHandler.onPostServerTick(FMLCommonHandler.java:247) ~[FMLCommonHandler.class:?]
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:590) ~[MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:396) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685) [li.class:?]
Caused by: java.lang.IllegalArgumentException
at net.minecraft.util.WeightedRandom.func_76273_a(WeightedRandom.java:28) ~[qv.class:?]
at net.minecraft.util.WeightedRandom.func_76271_a(WeightedRandom.java:60) ~[qv.class:?]
at net.minecraft.world.SpawnerAnimals.func_77191_a(SpawnerAnimals.java:235) ~[aho.class:?]
at net.minecraft.world.gen.ChunkProviderGenerate.func_73153_a(ChunkProviderGenerate.java:424) ~[aqz.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73153_a(ChunkProviderServer.java:279) ~[ms.class:?]
at net.minecraft.world.chunk.Chunk.func_76624_a(Chunk.java:1045) ~[apx.class:?]
at net.minecraftforge.common.chunkio.ChunkIOProvider.callStage2(ChunkIOProvider.java:52) ~[ChunkIOProvider.class:?]
at net.minecraftforge.common.chunkio.ChunkIOProvider.callStage2(ChunkIOProvider.java:12) ~[ChunkIOProvider.class:?]
at net.minecraftforge.common.util.AsynchronousExecutor.skipQueue(AsynchronousExecutor.java:344) ~[AsynchronousExecutor.class:?]
at net.minecraftforge.common.util.AsynchronousExecutor.getSkipQueue(AsynchronousExecutor.java:302) ~[AsynchronousExecutor.class:?]
at net.minecraftforge.common.chunkio.ChunkIOExecutor.syncChunkLoad(ChunkIOExecutor.java:12) ~[ChunkIOExecutor.class:?]
at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:126) ~[ms.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73158_c(ChunkProviderServer.java:101) ~[ms.class:?]
at net.minecraft.world.gen.ChunkProviderServer.func_73154_d(ChunkProviderServer.java:199) ~[ms.class:?]
at net.minecraft.world.World.func_72964_e(World.java:419) ~[ahb.class:?]
at net.minecraft.world.World.func_147439_a(World.java:345) ~[ahb.class:?]
... 25 more

Pretty much the same, I also have Railcraft 9.7.00 so I will look into that.

1.7 is no longer being updated. Feel free to submit a PR.

Can we have the crashlog that only blames Natura?

Hmmm, after some more testing it seams like it is some of the other mods that I have installed that is causing a conflict with Natura, maybe there is a update for that/those mod/s, I'll see if there is any...

(I'm guessing it is either Railcraft or malisis core)

(will write if I get it fixed if anyone else have the same problem)

It is a conflict or something with Railcraft version 9.5.0.0 and Natura version 2.2.0.1, it seams like both mods are trying to add stuff to the world at the same time or something?