[1.7.2][SOLVED] Why doesn't my Tile Entites persist or save info?

[00:05:07] [server thread/ERROR] [FML]: A TileEntity type ee.rot.blocks.TileEntityItemGenerator has throw an exception trying to write state. It will not persist. Report this to the mod author
java.lang.RuntimeException: class ee.rot.blocks.TileEntityItemGenerator is missing a mapping! This is a bug!
at net.minecraft.tileentity.TileEntity.writeToNBT(TileEntity.java:100) ~[TileEntity.class:?]
at ee.rot.blocks.TileEntityItemGenerator.writeToNBT(TileEntityItemGenerator.java:31) ~[TileEntityItemGenerator.class:?]
at net.minecraft.world.chunk.storage.AnvilChunkLoader.writeChunkToNBT(AnvilChunkLoader.java:323) [AnvilChunkLoader.class:?]
at net.minecraft.world.chunk.storage.AnvilChunkLoader.saveChunk(AnvilChunkLoader.java:132) [AnvilChunkLoader.class:?]
at net.minecraft.world.gen.ChunkProviderServer.safeSaveChunk(ChunkProviderServer.java:229) [ChunkProviderServer.class:?]
at net.minecraft.world.gen.ChunkProviderServer.saveChunks(ChunkProviderServer.java:281) [ChunkProviderServer.class:?]
at net.minecraft.world.WorldServer.saveAllChunks(WorldServer.java:875) [WorldServer.class:?]
at net.minecraft.server.MinecraftServer.saveAllWorlds(MinecraftServer.java:370) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:626) [MinecraftServer.class:?]
at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:118) [integratedServer.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:482) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:742) [MinecraftServer$2.class:?]

public class BlockItemGen extends BlockContainer
{

public BlockItemGen() {
	super(Material.iron);
	setHardness(5f);
	setResistance(10f);
}

@Override
public TileEntity createNewTileEntity(World var1, int var2) 
{
	return new TileEntityItemGenerator();
}

@Override
public boolean onBlockActivated(World world, int x, int y, int z, EntityPlayer player, int side, float hitX, float hitY, float hitZ) 
{
	if(!world.isRemote) {
		//FMLNetworkHandler.openGui(player, Main.instance, 0, world, x, y, z);
	}
	return true;
}

}

public class TileEntityItemGenerator extends TileEntity
{
private int MANA_CD = 55;
private int ACTION_CD = 25;
private int cd1 = ACTION_CD;
private int cd2 = MANA_CD;
private float mana = 0;
private float manaCost = 30;
private int range = 7;

@Override
public void writeToNBT(NBTTagCompound nbtTag) 
{		
	super.writeToNBT(nbtTag);
	nbtTag.setFloat("itemGenMana", mana);
	nbtTag.setInteger("itemGenCd1", cd1);
	nbtTag.setInteger("itemGenCd2", cd2);				
}

@Override
public void readFromNBT(NBTTagCompound nbtTag) 
{
	super.readFromNBT(nbtTag);
	mana = nbtTag.getFloat("itemGenMana");
	cd1 = nbtTag.getInteger("itemGenCd1");
	cd2 = nbtTag.getInteger("itemGenCd2");

}

@Override
public boolean canUpdate() 
{
	return true;
}

@Override
public void updateEntity() 
{
	if (cd2 == 0)
	{
		cd2 = MANA_CD;
		TileEntity te;
		for (int y = -range; y <= range; y++)
		{
			for (int x = -range; x <= range; x++)
			{
				for (int z = -range; z <= range; z++)
				{
					te = getWorldObj().getTileEntity(x + xCoord, y + yCoord, z + zCoord);
					if (te != null)
					{
						if (te instanceof TileEntityManaGenerator)
						{
							if (((TileEntityManaGenerator) te).getMana() >= 5f)
							mana += ((TileEntityManaGenerator) te).giveMana(5f);
						}
					}
				}
			}
		}
	}
	else cd2--;

	if (cd1 == 0)
	{
		if (mana >= manaCost)
		{
			cd1 = ACTION_CD;
			TileEntity te;
			for (int y = -range; y <= range; y++)
			{
				for (int x = -range; x <= range; x++)
				{
					for (int z = -range; z <= range; z++)
					{
						te = getWorldObj().getTileEntity(x + xCoord, y + yCoord, z + zCoord);
						if (te != null)
						{
							if (te instanceof TileEntityChest)
							{
								TileEntityChest tec = (TileEntityChest)te;
								for (int i = 0; i < tec.getSizeInventory(); i++)
								{
									if (tec.getStackInSlot(i) != null)
									{
										System.out.println(tec.getStackInSlot(i));
										tec.getStackInSlot(i).stackSize++;
										mana -= manaCost;
										if (mana < manaCost)return;
									}
								}								
							}
						}
					}
				}
			}
		}
	}
	else cd1--;
}	
}