Program: 81902
Project: 81902
Buggy source:
public static void onTickInGame(){
  if (FMLCommonHandler.instance() == null || FMLCommonHandler.instance().getMinecraftServerInstance() == null) {
    return;
  }
  World world=FMLCommonHandler.instance().getMinecraftServerInstance().worldServerForDimension(0);
  if (world != null && lastWorld != world) {
    lastWorld=world;
  }
  if (world != null) {
    if (world.getTotalWorldTime() % ConfigMisc.Misc_AutoDataSaveIntervalInTicks == 0) {
      Weather.writeOutData(false);
    }
  }
  World worlds[]=DimensionManager.getWorlds();
  for (int i=0; i < worlds.length; i++) {
    if (!lookupDimToWeatherMan.containsKey(worlds[i].provider.getDimension())) {
      if (WeatherUtilConfig.listDimensionsWeather.contains(worlds[i].provider.getDimension())) {
        addWorldToWeather(worlds[i].provider.getDimension());
      }
    }
    WeatherManagerServer wms=lookupDimToWeatherMan.get(worlds[i].provider.getDimension());
    if (wms != null) {
      lookupDimToWeatherMan.get(worlds[i].provider.getDimension()).tick();
    }
  }
  boolean testRainRequest=false;
  if (testRainRequest) {
    List<IMCMessage> listMsgs=new ArrayList<IMCMessage>();
    listMsgs=FMLInterModComms.fetchRuntimeMessages(Weather.modID);
    for (int i=0; i < listMsgs.size(); i++) {
      if (listMsgs.get(i).key.equals("String_Node_Str")) {
        NBTTagCompound nbt=listMsgs.get(i).getNBTValue();
        String replyMod=nbt.getString("String_Node_Str");
        nbt.setBoolean("String_Node_Str",true);
        FMLInterModComms.sendRuntimeMessage(replyMod,replyMod,"String_Node_Str",nbt);
      }
    }
  }
  boolean debugIMC=false;
  if (debugIMC) {
    try {
      List<IMCMessage> listMsgs=new ArrayList<IMCMessage>();
      listMsgs=FMLInterModComms.fetchRuntimeMessages(Weather.modID);
      for (int i=0; i < listMsgs.size(); i++) {
      }
    }
 catch (    Exception ex) {
      ex.printStackTrace();
    }
  }
  boolean testCustomLightning=false;
  if (testCustomLightning) {
    if (world.getTotalWorldTime() % 20 == 0) {
      EntityPlayer player=world.getClosestPlayer(0,0,0,-1,false);
      if (player != null) {
        EntityLightningBoltCustom lightning=new EntityLightningBoltCustom(world,player.posX,player.posY,player.posZ);
        world.addWeatherEffect(lightning);
        lookupDimToWeatherMan.get(0).syncLightningNew(lightning,true);
      }
    }
  }
  boolean derp=true;
  if (derp) {
    if (world.getTotalWorldTime() % 2 == 0) {
      EntityPlayer player=world.getClosestPlayer(0,0,0,-1,false);
      if (player != null) {
        ItemStack is=player.getItemStackFromSlot(EntityEquipmentSlot.MAINHAND);
        if (is != null && is.getItem() instanceof ItemSpade) {
          int y=world.getHeight(new BlockPos(player.posX,0,player.posZ)).getY();
          System.out.println("String_Node_Str" + y);
          WeatherUtilBlock.fillAgainstWallSmoothly(player.worldObj,new Vec3(player.posX,y + 0.5D,player.posZ),player.rotationYawHead,15,2,CommonProxy.blockSandLayer);
        }
      }
    }
  }
}

Fixed version (ground truth):
public static void onTickInGame(){
  if (FMLCommonHandler.instance() == null || FMLCommonHandler.instance().getMinecraftServerInstance() == null) {
    return;
  }
  World world=FMLCommonHandler.instance().getMinecraftServerInstance().worldServerForDimension(0);
  if (world != null && lastWorld != world) {
    lastWorld=world;
  }
  if (world != null) {
    if (world.getTotalWorldTime() % ConfigMisc.Misc_AutoDataSaveIntervalInTicks == 0) {
      Weather.writeOutData(false);
    }
  }
  World worlds[]=DimensionManager.getWorlds();
  for (int i=0; i < worlds.length; i++) {
    if (!lookupDimToWeatherMan.containsKey(worlds[i].provider.getDimension())) {
      if (WeatherUtilConfig.listDimensionsWeather.contains(worlds[i].provider.getDimension())) {
        addWorldToWeather(worlds[i].provider.getDimension());
      }
    }
    WeatherManagerServer wms=lookupDimToWeatherMan.get(worlds[i].provider.getDimension());
    if (wms != null) {
      lookupDimToWeatherMan.get(worlds[i].provider.getDimension()).tick();
    }
  }
  boolean testRainRequest=false;
  if (testRainRequest) {
    List<IMCMessage> listMsgs=new ArrayList<IMCMessage>();
    listMsgs=FMLInterModComms.fetchRuntimeMessages(Weather.modID);
    for (int i=0; i < listMsgs.size(); i++) {
      if (listMsgs.get(i).key.equals("String_Node_Str")) {
        NBTTagCompound nbt=listMsgs.get(i).getNBTValue();
        String replyMod=nbt.getString("String_Node_Str");
        nbt.setBoolean("String_Node_Str",true);
        FMLInterModComms.sendRuntimeMessage(replyMod,replyMod,"String_Node_Str",nbt);
      }
    }
  }
  boolean debugIMC=false;
  if (debugIMC) {
    try {
      List<IMCMessage> listMsgs=new ArrayList<IMCMessage>();
      listMsgs=FMLInterModComms.fetchRuntimeMessages(Weather.modID);
      for (int i=0; i < listMsgs.size(); i++) {
      }
    }
 catch (    Exception ex) {
      ex.printStackTrace();
    }
  }
  boolean testCustomLightning=false;
  if (testCustomLightning) {
    if (world.getTotalWorldTime() % 20 == 0) {
      EntityPlayer player=world.getClosestPlayer(0,0,0,-1,false);
      if (player != null) {
        EntityLightningBoltCustom lightning=new EntityLightningBoltCustom(world,player.posX,player.posY,player.posZ);
        world.addWeatherEffect(lightning);
        lookupDimToWeatherMan.get(0).syncLightningNew(lightning,true);
      }
    }
  }
  boolean derp=false;
  if (derp) {
    if (world.getTotalWorldTime() % 2 == 0) {
      EntityPlayer player=world.getClosestPlayer(0,0,0,-1,false);
      if (player != null) {
        ItemStack is=player.getItemStackFromSlot(EntityEquipmentSlot.MAINHAND);
        if (is != null && is.getItem() instanceof ItemSpade) {
          int y=world.getHeight(new BlockPos(player.posX,0,player.posZ)).getY();
          System.out.println("String_Node_Str" + y);
          WeatherUtilBlock.fillAgainstWallSmoothly(player.worldObj,new Vec3(player.posX,y + 0.5D,player.posZ),player.rotationYawHead,15,2,CommonProxy.blockSandLayer);
        }
      }
    }
  }
}