java.lang.RuntimeException: class net.minecraft.src.TileEntity is missing a mapping! This is a bug!
	at net.minecraft.src.TileEntity.writeToNBT(TileEntity.java:49)
	at net.minecraft.src.ChunkLoader.storeChunkInCompound(ChunkLoader.java:176)
	at net.minecraft.src.McRegionChunkLoader.saveChunk(McRegionChunkLoader.java:66)
	at net.minecraft.src.ChunkProvider.func_28062_b(ChunkProvider.java:132)
	at net.minecraft.src.ChunkProvider.saveChunks(ChunkProvider.java:168)
	at net.minecraft.src.World.saveWorld(World.java:295)
	at net.minecraft.src.World.saveWorldIndirectly(World.java:1991)
	at net.minecraft.client.Minecraft.changeWorld(Minecraft.java:1292)
	at net.minecraft.client.Minecraft.changeWorld2(Minecraft.java:1276)
	at net.minecraft.client.Minecraft.changeWorld1(Minecraft.java:1271)
	at net.minecraft.client.Minecraft.func_28002_e(Minecraft.java:607)
	at net.minecraft.client.Minecraft.run(Minecraft.java:579)
	at java.lang.Thread.run(Thread.java:680)
java.lang.ClassCastException: net.minecraft.src.TileEntity cannot be cast to net.minecraft.src.TileEntityExtractor
	at net.minecraft.src.BlockCocoaExtractor.blockActivated(BlockCocoaExtractor.java:69)
	at net.minecraft.src.PlayerControllerTest.sendPlaceBlock(PlayerControllerTest.java:60)
	at net.minecraft.client.Minecraft.clickMouse(Minecraft.java:828)
	at net.minecraft.client.Minecraft.runTick(Minecraft.java:1118)
	at net.minecraft.client.Minecraft.run(Minecraft.java:483)
	at java.lang.Thread.run(Thread.java:680)