WORLDEDIT-2576 - Reported by squirlemaster

When I try to use World Edit I get this error code:
8:50 PM [SEVERE] java.lang.NoClassDefFoundError: net/minecraft/server/Block
08:50 PM [SEVERE] at com.sk89q.worldedit.bukkit.BukkitWorld.isValidBlockType(BukkitWorld.java:872)
08:50 PM [SEVERE] at com.sk89q.worldedit.WorldEdit.getBlock(WorldEdit.java:414)
08:50 PM [SEVERE] at com.sk89q.worldedit.WorldEdit.getBlock(WorldEdit.java:355)
08:50 PM [SEVERE] at com.sk89q.worldedit.WorldEdit.getBlock(WorldEdit.java:549)
08:50 PM [SEVERE] at com.sk89q.worldedit.WorldEdit.getBlockPattern(WorldEdit.java:608)
08:50 PM [SEVERE] at com.sk89q.worldedit.commands.RegionCommands.set(RegionCommands.java:74)
08:50 PM [SEVERE] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
08:50 PM [SEVERE] at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
08:50 PM [SEVERE] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
08:50 PM [SEVERE] at java.lang.reflect.Method.invoke(Unknown Source)
08:50 PM [SEVERE] at com.sk89q.minecraft.util.commands.CommandsManager.invokeMethod(CommandsManager.java:522)
08:50 PM [SEVERE] at com.sk89q.worldedit.WorldEdit$1.invokeMethod(WorldEdit.java:241)
08:50 PM [SEVERE] at com.sk89q.worldedit.WorldEdit$1.invokeMethod(WorldEdit.java:172)
08:50 PM [SEVERE] at com.sk89q.minecraft.util.commands.CommandsManager.executeMethod(CommandsManager.java:509)
08:50 PM [SEVERE] at com.sk89q.minecraft.util.commands.CommandsManager.execute(CommandsManager.java:425)
08:50 PM [SEVERE] at com.sk89q.worldedit.WorldEdit.handleCommand(WorldEdit.java:1339)
08:50 PM [SEVERE] at com.sk89q.worldedit.bukkit.WorldEditPlugin.onCommand(WorldEditPlugin.java:197)
08:50 PM [SEVERE] at com.sk89q.bukkit.util.DynamicPluginCommand.execute(DynamicPluginCommand.java:52)
08:50 PM [SEVERE] at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:186)
08:50 PM [SEVERE] at org.bukkit.craftbukkit.v1_4_6.CraftServer.dispatchCommand(CraftServer.java:510)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.PlayerConnection.handleCommand(PlayerConnection.java:980)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.PlayerConnection.chat(PlayerConnection.java:898)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.PlayerConnection.a(PlayerConnection.java:853)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.Packet3Chat.handle(Packet3Chat.java:44)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.NetworkManager.b(NetworkManager.java:290)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.PlayerConnection.d(PlayerConnection.java:112)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.ServerConnection.b(SourceFile:39)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.DedicatedServerConnection.b(SourceFile:30)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.MinecraftServer.r(MinecraftServer.java:598)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.DedicatedServer.r(DedicatedServer.java:224)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.MinecraftServer.q(MinecraftServer.java:494)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.MinecraftServer.run(MinecraftServer.java:427)
08:50 PM [SEVERE] at net.minecraft.server.v1_4_6.ThreadServerApplication.run(SourceFile:849)
08:50 PM [SEVERE] Caused by: java.lang.ClassNotFoundException: net.minecraft.server.Block
08:50 PM [SEVERE] at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader.java:70)
08:50 PM [SEVERE] at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:53)
08:50 PM [SEVERE] at java.lang.ClassLoader.loadClass(Unknown Source)
08:50 PM [SEVERE] ... 33 more
08:50 PM [SEVERE] Could not pass event EntityChangeBlockEvent to WorldGuard v5.6.5