java.lang.NoClassDefFoundError: net/minecraft/client/renderer/texture/IconRegister
	at java.lang.Class.getDeclaredMethods0(Native Method)
	at java.lang.Class.privateGetDeclaredMethods(Class.java:2531)
	at java.lang.Class.getMethod0(Class.java:2774)
	at java.lang.Class.getMethod0(Class.java:2783)
	at java.lang.Class.getMethod0(Class.java:2783)
	at java.lang.Class.getMethod(Class.java:1663)
	at calclavia.lib.prefab.block.BlockAdvanced.isUsableWrench(BlockAdvanced.java:87)
	at calclavia.lib.prefab.block.BlockAdvanced.func_71903_a(BlockAdvanced.java:41)
	at net.minecraft.item.ItemInWorldManager.func_73078_a(ItemInWorldManager.java:524)
	at net.minecraft.network.NetServerHandler.func_72472_a(NetServerHandler.java:896)
	at net.minecraft.network.packet.Packet15Place.func_73279_a(Packet15Place.java:79)
	at net.minecraft.network.TcpConnection.func_74428_b(TcpConnection.java:470)
	at net.minecraft.network.NetServerHandler.func_72570_d(NetServerHandler.java:233)
	at net.minecraft.network.NetworkListenThread.func_71747_b(NetworkListenThread.java:54)
	at net.minecraft.server.dedicated.DedicatedServerListenThread.func_71747_b(DedicatedServerListenThread.java:34)
	at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:914)
	at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:330)
	at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:781)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:663)
	at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:16)
Caused by: java.lang.ClassNotFoundException: net.minecraft.client.renderer.texture.IconRegister
	at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:186)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
	... 20 more
Caused by: java.lang.RuntimeException: Attempted to load class mt for invalid side SERVER
	at cpw.mods.fml.common.asm.transformers.SideTransformer.transform(SideTransformer.java:51)
	at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:274)
	at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:172)
	... 22 more