[SEVERE] Could not pass event SignChangeEvent to BuyLand v0.6.1
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.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:26)
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:479)
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:464)
	at net.minecraft.server.v1_5_R2.PlayerConnection.a(PlayerConnection.java:1387)
	at net.minecraft.server.v1_5_R2.Packet130UpdateSign.handle(SourceFile:46)
	at org.spigotmc.netty.NettyNetworkManager.b(NettyNetworkManager.java:176)
	at net.minecraft.server.v1_5_R2.PlayerConnection.d(PlayerConnection.java:110)
	at net.minecraft.server.v1_5_R2.ServerConnection.b(SourceFile:35)
	at org.spigotmc.netty.NettyServerConnection.b(NettyServerConnection.java:66)
	at net.minecraft.server.v1_5_R2.MinecraftServer.r(MinecraftServer.java:580)
	at net.minecraft.server.v1_5_R2.DedicatedServer.r(DedicatedServer.java:229)
	at net.minecraft.server.v1_5_R2.MinecraftServer.q(MinecraftServer.java:469)
	at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:401)
	at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573)
Caused by: java.lang.ClassCastException: org.bukkit.craftbukkit.v1_5_R2.block.CraftBlockState cannot be cast to org.bukkit.block.Sign
	at me.buyland.buyland.ServerChatPlayerListener.onSignChange(ServerChatPlayerListener.java:148)
	at sun.reflect.GeneratedMethodAccessor585.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425)
	... 15 more