Error Report

java.lang.AbstractMethodError: simcraft.machines.workshop.TileEntityWorkBench.func_70301_a(I)Lnet/minecraft/item/ItemStack;
	at simcraft.machines.InventorySubCraft.func_70301_a(InventorySubCraft.java:35)
	at net.minecraft.item.crafting.CraftingManager.func_82787_a(CraftingManager.java:267)
	at simcraft.machines.workshop.ContainerWorkBnch.func_75130_a(ContainerWorkBnch.java:107)
	at simcraft.machines.workshop.ContainerWorkBnch.<init>(ContainerWorkBnch.java:98)
	at simcraft.core.GuiHandler.getServerGuiElement(GuiHandler.java:146)
	at cpw.mods.fml.common.network.NetworkRegistry.openRemoteGui(NetworkRegistry.java:308)
	at cpw.mods.fml.common.network.FMLNetworkHandler.openGui(FMLNetworkHandler.java:352)
	at net.minecraft.entity.player.EntityPlayer.openGui(EntityPlayer.java:2396)
	at simcraft.machines.workshop.blockWorkBench.func_71903_a(blockWorkBench.java:428)
	at net.minecraft.item.ItemInWorldManager.func_73078_a(ItemInWorldManager.java:412)
	at net.minecraft.network.NetServerHandler.func_72472_a(NetServerHandler.java:553)
	at net.minecraft.network.packet.Packet15Place.func_73279_a(SourceFile:58)
	at net.minecraft.network.MemoryConnection.func_74428_b(MemoryConnection.java:89)
	at net.minecraft.network.NetServerHandler.func_72570_d(NetServerHandler.java:134)
	at net.minecraft.network.NetworkListenThread.func_71747_b(NetworkListenThread.java:53)
	at net.minecraft.server.integrated.IntegratedServerListenThread.func_71747_b(IntegratedServerListenThread.java:109)
	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:677)
	at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:573)
	at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:127)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:470)
	at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:573)