[help] help with worldguard [Minecraft]

[Ofir aviel]

hi, i have a Minecraft server, but every time i am trying to define a space, i get this error in the console:

 [Server thread/WARN]: [WorldGuard] WorldGuard encountered an unexpected error
java.lang.NoSuchMethodError: com.google.common.base.Preconditions.checkState(ZLjava/lang/String;Ljava/lang/Object;)V
	at com.sk89q.worldguard.internal.guava.util.concurrent.Futures.getDone(Futures.java:1170) ~[WorldGuard.jar:?]
	at com.sk89q.worldguard.internal.guava.util.concurrent.Futures$4.run(Futures.java:1121) [WorldGuard.jar:?]
	at com.sk89q.worldguard.internal.guava.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:435) [WorldGuard.jar:?]
	at com.sk89q.worldguard.internal.guava.util.concurrent.AbstractFuture.executeListener(AbstractFuture.java:900) [WorldGuard.jar:?]
	at com.sk89q.worldguard.internal.guava.util.concurrent.AbstractFuture.addListener(AbstractFuture.java:634) [WorldGuard.jar:?]
	at com.sk89q.worldguard.internal.guava.util.concurrent.AbstractFuture$TrustedFuture.addListener(AbstractFuture.java:98) [WorldGuard.jar:?]
	at com.sk89q.worldguard.internal.guava.util.concurrent.Futures.addCallback(Futures.java:1135) [WorldGuard.jar:?]
	at com.sk89q.worldguard.internal.guava.util.concurrent.Futures.addCallback(Futures.java:1073) [WorldGuard.jar:?]
	at com.sk89q.worldguard.bukkit.commands.AsyncCommandHelper.thenRespondWith(AsyncCommandHelper.java:78) [WorldGuard.jar:?]
	at com.sk89q.worldguard.bukkit.commands.region.RegionCommands.define(RegionCommands.java:140) [WorldGuard.jar:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_131]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_131]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_131]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_131]
	at com.sk89q.minecraft.util.commands.CommandsManager.invokeMethod(CommandsManager.java:528) [WorldEdit.jar:?]
	at com.sk89q.minecraft.util.commands.CommandsManager.executeMethod(CommandsManager.java:516) [WorldEdit.jar:?]
	at com.sk89q.minecraft.util.commands.CommandsManager.executeMethod(CommandsManager.java:471) [WorldEdit.jar:?]
	at com.sk89q.minecraft.util.commands.CommandsManager.execute(CommandsManager.java:409) [WorldEdit.jar:?]
	at com.sk89q.worldguard.bukkit.WorldGuardPlugin.onCommand(WorldGuardPlugin.java:295) [WorldGuard.jar:?]
	at com.sk89q.bukkit.util.DynamicPluginCommand.execute(DynamicPluginCommand.java:54) [WorldEdit.jar:?]
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) [spigot.jar:git-Spigot-fdc1440-53fac9f]
	at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:641) [spigot.jar:git-Spigot-fdc1440-53fac9f]
	at net.minecraft.server.v1_8_R3.PlayerConnection.handleCommand(PlayerConnection.java:1162) [spigot.jar:git-Spigot-fdc1440-53fac9f]
	at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:997) [spigot.jar:git-Spigot-fdc1440-53fac9f]
	at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:45) [spigot.jar:git-Spigot-fdc1440-53fac9f]
	at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:1) [spigot.jar:git-Spigot-fdc1440-53fac9f]
	at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [spigot.jar:git-Spigot-fdc1440-53fac9f]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_131]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_131]
	at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [spigot.jar:git-Spigot-fdc1440-53fac9f]
	at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:714) [spigot.jar:git-Spigot-fdc1440-53fac9f]
	at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [spigot.jar:git-Spigot-fdc1440-53fac9f]
	at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:653) [spigot.jar:git-Spigot-fdc1440-53fac9f]
	at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:556) [spigot.jar:git-Spigot-fdc1440-53fac9f]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_131]

can you help me with that error?

thank you