clickwarp error

[SEVERE] Could not pass event PlayerInteractEvent to ClickWarp v1.3.1
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:427)
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:477)
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:462)
	at org.bukkit.craftbukkit.v1_5_R2.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:185)
	at net.minecraft.server.v1_5_R2.PlayerInteractManager.interact(PlayerInteractManager.java:370)
	at net.minecraft.server.v1_5_R2.PlayerConnection.a(PlayerConnection.java:632)
	at net.minecraft.server.v1_5_R2.Packet15Place.handle(SourceFile:58)
	at net.minecraft.server.v1_5_R2.NetworkManager.b(NetworkManager.java:292)
	at net.minecraft.server.v1_5_R2.PlayerConnection.d(PlayerConnection.java:110)
	at net.minecraft.server.v1_5_R2.ServerConnection.b(SourceFile:35)
	at net.minecraft.server.v1_5_R2.DedicatedServerConnection.b(SourceFile:30)
	at net.minecraft.server.v1_5_R2.MinecraftServer.r(MinecraftServer.java:580)
	at net.minecraft.server.v1_5_R2.DedicatedServer.r(DedicatedServer.java:225)
	at net.minecraft.server.v1_5_R2.MinecraftServer.q(MinecraftServer.java:476)
	at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:409)
	at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573)
Caused by: java.lang.NullPointerException
	at org.bukkit.ChatColor.translateAlternateColorCodes(ChatColor.java:203)
	at de.comniemeer.ClickWarp.Listeners.SignListener.onPlayerInteract(SignListener.java:82)
	at sun.reflect.GeneratedMethodAccessor125.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425)
	... 16 more