Bukkit

What steps will reproduce the problem?
1.Build a portal
2.Destroy one block of outer edge
3.

What is the expected output? What do you see instead?
Expect portal to deactivate, instead only the portal block adjacent to the removed block is removed, the others stay and the portal is still functional

What version of the product are you using?
2.1

Do you have an error log of what happened?

No errors when destroying the block, but when I'm in a portal this happens:

12:37:39 [SEVERE] Could not pass event PLAYER_PORTAL to PermissionsEx
java.lang.NullPointerException
        at ru.tehkode.permissions.bukkit.BukkitPermissions$PlayerEvents.onPlayerPortal(BukkitPermissions.java:187)
        at org.bukkit.plugin.java.JavaPluginLoader$10.execute(JavaPluginLoader.java:307)
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:58)
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:338)
        at net.minecraft.server.ServerConfigurationManager.f(ServerConfigurationManager.java:295)
        at net.minecraft.server.EntityPlayer.a(EntityPlayer.java:244)
        at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:299)
        at net.minecraft.server.Packet10Flying.a(SourceFile:126)
        at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)
        at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:89)
        at net.minecraft.server.NetworkListenThread.a(SourceFile:105)
        at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:454)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:363)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:422)

Please provide any additional information below.