Identify Tome error

2012-12-28 00:50:20 [SEVERE] Could not pass event PlayerInteractEvent to DiabloDrops v2.2.377<br />
org.bukkit.event.EventException<br />
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:427)<br />
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)<br />
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:477)<br />
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:462)<br />
at org.bukkit.craftbukkit.v1_4_6.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:178)<br />
at net.minecraft.server.v1_4_6.PlayerInteractManager.interact(PlayerInteractManager.java:376)<br />
at net.minecraft.server.v1_4_6.PlayerConnection.a(PlayerConnection.java:657)<br />
at net.minecraft.server.v1_4_6.Packet15Place.handle(SourceFile:58)<br />
at net.minecraft.server.v1_4_6.NetworkManager.b(NetworkManager.java:290)<br />
at net.minecraft.server.v1_4_6.PlayerConnection.d(PlayerConnection.java:112)<br />
at net.minecraft.server.v1_4_6.ServerConnection.b(SourceFile:39)<br />
at net.minecraft.server.v1_4_6.DedicatedServerConnection.b(SourceFile:30)<br />
at net.minecraft.server.v1_4_6.MinecraftServer.r(MinecraftServer.java:598)<br />
at net.minecraft.server.v1_4_6.DedicatedServer.r(DedicatedServer.java:224)<br />
at net.minecraft.server.v1_4_6.MinecraftServer.q(MinecraftServer.java:494)<br />
at net.minecraft.server.v1_4_6.MinecraftServer.run(MinecraftServer.java:427)<br />
at net.minecraft.server.v1_4_6.ThreadServerApplication.run(SourceFile:849)<br />
Caused by: java.lang.NullPointerException<br />
at org.bukkit.ChatColor.getLastColors(ChatColor.java:221)<br />
at com.modcrafting.diablodrops.listeners.TomeListener.onRightClick(TomeListener.java:87)<br />
at sun.reflect.GeneratedMethodAccessor43.invoke(Unknown Source)<br />
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)<br />
at java.lang.reflect.Method.invoke(Method.java:601)<br />
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425)<br />
... 16 more<br />