Problem/Bug GriefPrevention

Almost all commands say: "An internal error occurred while attempting to perform this command"

(/trust, /containertrust, /untrust, etc)

And the console displays these errors:

Code:

[10:10:58] [Server thread/INFO]: _GUW_ issued server command: /trust brunasantosyt
[10:10:58] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'trust' in plugin GriefPrevention v8.6.4
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:196) ~[craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at org.bukkit.craftbukkit.v1_7_R1.CraftServer.dispatchCommand(CraftServer.java:542) ~[craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at net.minecraft.server.v1_7_R1.PlayerConnection.handleCommand(PlayerConnection.java:932) [craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:814) [craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at net.minecraft.server.v1_7_R1.PacketPlayInChat.a(PacketPlayInChat.java:28) [craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at net.minecraft.server.v1_7_R1.PacketPlayInChat.handle(PacketPlayInChat.java:47) [craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146) [craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:655) [craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) [craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) [craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
Caused by: java.lang.NoSuchMethodError: org.bukkit.OfflinePlayer.getUniqueId()Ljava/util/UUID;
at me.ryanhamshire.GriefPrevention.GriefPrevention.handleTrustCommand(GriefPrevention.java:2056) ~[?:?]
at me.ryanhamshire.GriefPrevention.GriefPrevention.onCommand(GriefPrevention.java:947) ~[?:?]
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[craftbukkit172.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
... 13 more

Help me please.

Note: Commands / abandonclaim, / trustlist. They work

1.7.2
Release: 8.1.3

 

@TheGuw
Why are you on 1.7.2? You should really update since your server is prone to hacks.

As for your issue. The error was cause by this issue
Caused by: java.lang.NoSuchMethodError: org.bukkit.OfflinePlayer.getUniqueId()Ljava/util/UUID;

Code:

Caused by: java.lang.NoSuchMethodError: org.bukkit.OfflinePlayer.getUniqueId()Ljava/util/UUID;

Are you sure the user is online?

 

@TheGuw
Why are you still on 1.7? There is no reason to stay on an outdated version. Update your server.

That plugin requires UUIDs, which are only present in 1.8 and up. You need to update your server.