java.lang.NoClassDefFoundError: ic2/common/EnergyNet$EnergyNet$EnergyTarget
        at ic2.common.EnergyNet.getValidReceivers(EnergyNet.java:561)
        at ic2.common.EnergyNet.discover(EnergyNet.java:411)
        at ic2.common.EnergyNet.addTileEntity(EnergyNet.java:123)
        at ic2.common.TileEntityCable.b_(TileEntityCable.java:77)
        at rv.l(World.java:1472)
        at net.minecraft.client.Minecraft.k(SourceFile:1384)
        at net.minecraft.client.Minecraft.run(SourceFile:666)
        at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: ic2.common.EnergyNet$EnergyNet$EnergyTarget
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 8 more