Bukkit

ERROR:
[15:47:00] [Server thread/WARN]: [ColoredTablist] Task #41 for ColoredTablist v2.1.1 generated an exception
java.lang.NullPointerException
    at net.milkbowl.vault.permission.plugins.Permission_GroupManager.getPrimaryGroup(Permission_GroupManager.java:327) ~[?:?]
    at net.milkbowl.vault.permission.Permission.getPrimaryGroup(Permission.java:644) ~[?:?]
    at com.mcheaven.coloredtablist.CT_ColorGroups.init(CT_ColorGroups.java:10) ~[?:?]
    at com.mcheaven.coloredtablist.CT_Listener.useGroups(CT_Listener.java:136) ~[?:?]
    at com.mcheaven.coloredtablist.CT_Listener.access$1(CT_Listener.java:128) ~[?:?]
    at com.mcheaven.coloredtablist.CT_Listener$1.run(CT_Listener.java:105) ~[?:?]
    at org.bukkit.craftbukkit.v1_7_R1.scheduler.CraftTask.run(CraftTask.java:53) ~[minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at org.bukkit.craftbukkit.v1_7_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345) [minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:587) [minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) [minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) [minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]

And then again an Error:
[15:47:08] [Server thread/WARN]: [ColoredTablist] Task #52 for ColoredTablist v2.1.1 generated an exception
java.lang.NullPointerException
    at net.milkbowl.vault.permission.plugins.Permission_GroupManager.getPrimaryGroup(Permission_GroupManager.java:327) ~[?:?]
    at net.milkbowl.vault.permission.Permission.getPrimaryGroup(Permission.java:644) ~[?:?]
    at com.mcheaven.coloredtablist.CT_ColorGroups.init(CT_ColorGroups.java:10) ~[?:?]
    at com.mcheaven.coloredtablist.CT_Listener.useGroups(CT_Listener.java:136) ~[?:?]
    at com.mcheaven.coloredtablist.CT_Listener.access$1(CT_Listener.java:128) ~[?:?]
    at com.mcheaven.coloredtablist.CT_Listener$1.run(CT_Listener.java:105) ~[?:?]
    at org.bukkit.craftbukkit.v1_7_R1.scheduler.CraftTask.run(CraftTask.java:53) ~[minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at org.bukkit.craftbukkit.v1_7_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:345) [minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:587) [minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) [minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) [minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
    at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [minecraft_server.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]

And Again and again I think the Error came 15 times...