FATAL: Exception during Mapping Collection from Mapper

[chezpaul]

Got this error in server console.

[11:06:57 FATAL]: Exception during Mapping Collection from Mapper moze_intel.projecte.emc.mappers.FluidMapper. PLEASE REPORT THIS! EMC VALUES MIGHT BE INCONSISTENT!
[11:06:57 WARN]: java.lang.NullPointerException: null key in entry: null=1
[11:06:57 WARN]: at com.google.common.collect.CollectPreconditions.checkEntryNotNull(CollectPreconditions.java:31)
[11:06:57 WARN]: at com.google.common.collect.ImmutableMap.entryOf(ImmutableMap.java:135)
[11:06:57 WARN]: at com.google.common.collect.ImmutableMap.of(ImmutableMap.java:89)
[11:06:57 WARN]: at moze_intel.projecte.emc.mappers.FluidMapper.addMappings(FluidMapper.java:109)
[11:06:57 WARN]: at moze_intel.projecte.emc.EMCMapper.map(EMCMapper.java:98)
[11:06:57 WARN]: at moze_intel.projecte.PECore.serverStarting(PECore.java:143)
[11:06:57 WARN]: at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[11:06:57 WARN]: at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[11:06:57 WARN]: at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[11:06:57 WARN]: at java.lang.reflect.Method.invoke(Method.java:498)
[11:06:57 WARN]: at cpw.mods.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:532)
[11:06:57 WARN]: at sun.reflect.GeneratedMethodAccessor3.invoke(Unknown Source)
[11:06:57 WARN]: at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[11:06:57 WARN]: at java.lang.reflect.Method.invoke(Method.java:498)
[11:06:57 WARN]: at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
[11:06:57 WARN]: at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
[11:06:57 WARN]: at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
[11:06:57 WARN]: at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
[11:06:57 WARN]: at com.google.common.eventbus.EventBus.post(EventBus.java:275)
[11:06:57 WARN]: at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:212)
[11:06:57 WARN]: at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:190)
[11:06:57 WARN]: at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[11:06:57 WARN]: at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[11:06:57 WARN]: at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[11:06:57 WARN]: at java.lang.reflect.Method.invoke(Method.java:498)
[11:06:57 WARN]: at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
[11:06:57 WARN]: at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
[11:06:57 WARN]: at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
[11:06:57 WARN]: at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
[11:06:57 WARN]: at com.google.common.eventbus.EventBus.post(EventBus.java:275)
[11:06:57 WARN]: at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:119)
[11:06:57 WARN]: at cpw.mods.fml.common.Loader.serverStarting(Loader.java:789)
[11:06:57 WARN]: at cpw.mods.fml.common.FMLCommonHandler.handleServerStarting(FMLCommonHandler.java:283)
[11:06:57 WARN]: at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:368)
[11:06:57 WARN]: at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:643)
[11:06:57 WARN]: at java.lang.Thread.run(Thread.java:745)
[11:06:57 INFO]: Collected Mappings from moze_intel.projecte.emc.mappers.SmeltingMapper
[11:06:57 INFO]: Collected Mappings from moze_intel.projecte.emc.mappers.APICustomConversionMapper
[11:06:57 INFO]: Mapping Collection finished