Main mod class:

@Mod(modid = ExampleMod.MODID, version = ExampleMod.VERSION, acceptableRemoteVersions = "*")
public class ExampleMod
{
    public static final String MODID = "wanderlust";
    public static final String VERSION = "1.0";

    @EventHandler
    public void init(FMLInitializationEvent event)
    {
        System.out.println("DIRT BLOCK >> "+Blocks.DIRT.getUnlocalizedName());
        GameRegistry.registerWorldGenerator(new RoadWorldGenerator(), 1);
        MinecraftForge.EVENT_BUS.register(new loadUnloadSaveListener());
    }
}

World generator:

public final class RoadWorldGenerator implements IWorldGenerator
{
    /*
    Code unrelated to problem.
    */

    @Override
    public void generate(Random          random,
                         int             chunkX,
                         int             chunkZ,
                         World           world,
                         IChunkGenerator chunkGenerator,
                         IChunkProvider  chunkProvider)
    {
        int blockX = chunkX * 16;
        int blockZ = chunkZ * 16;

        world.setBlockState(new BlockPos(blockX + 8, 20, blockZ + 8), Blocks.STONEBRICK.getDefaultState(), 2);

        RoadMap roadmap = RoadMapRegistry.get(world.provider.getDimension());

        /*
        Code unrelated to problem.
        */
    }
}