Prowalls error

[20:24:54] [Server thread/ERROR]: Error occurred while enabling ProWalls v0.2.12 (Is it up to date?)
java.lang.NoClassDefFoundError: com/sk89q/worldedit/IncompleteRegionException
	at de.rob1n.prowalls.cmd.CommandList.<init>(CommandList.java:17) ~[?:?]
	at de.rob1n.prowalls.cmd.CommandHandler.<init>(CommandHandler.java:22) ~[?:?]
	at de.rob1n.prowalls.ProWalls.onEnable(ProWalls.java:75) ~[?:?]
	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:321) ~[custom.jar:git-Spigot-13716d9-0e2396c]
	at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:335) [custom.jar:git-Spigot-13716d9-0e2396c]
	at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405) [custom.jar:git-Spigot-13716d9-0e2396c]
	at org.bukkit.craftbukkit.v1_8_R1.CraftServer.loadPlugin(CraftServer.java:355) [custom.jar:git-Spigot-13716d9-0e2396c]
	at org.bukkit.craftbukkit.v1_8_R1.CraftServer.enablePlugins(CraftServer.java:315) [custom.jar:git-Spigot-13716d9-0e2396c]
	at net.minecraft.server.v1_8_R1.MinecraftServer.q(MinecraftServer.java:402) [custom.jar:git-Spigot-13716d9-0e2396c]
	at net.minecraft.server.v1_8_R1.MinecraftServer.k(MinecraftServer.java:370) [custom.jar:git-Spigot-13716d9-0e2396c]
	at net.minecraft.server.v1_8_R1.MinecraftServer.a(MinecraftServer.java:325) [custom.jar:git-Spigot-13716d9-0e2396c]
	at net.minecraft.server.v1_8_R1.DedicatedServer.init(DedicatedServer.java:211) [custom.jar:git-Spigot-13716d9-0e2396c]
	at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:494) [custom.jar:git-Spigot-13716d9-0e2396c]
	at java.lang.Thread.run(Unknown Source) [?:1.7.0_60]
Caused by: java.lang.ClassNotFoundException: com.sk89q.worldedit.IncompleteRegionException
	at java.net.URLClassLoader$1.run(Unknown Source) ~[?:1.7.0_60]
	at java.net.URLClassLoader$1.run(Unknown Source) ~[?:1.7.0_60]
	at java.security.AccessController.doPrivileged(Native Method) ~[?:1.7.0_60]
	at java.net.URLClassLoader.findClass(Unknown Source) ~[?:1.7.0_60]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:101) ~[custom.jar:git-Spigot-13716d9-0e2396c]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86) ~[custom.jar:git-Spigot-13716d9-0e2396c]
	at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.7.0_60]
	at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.7.0_60]
	... 14 more