Error Log

[12:04:40 INFO]: Polar_Wolfs issued server command: /commandstore
[12:04:42 ERROR]: Could not pass event InventoryClickEvent to PurchaseCommands v
0.1
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:302) ~[craftbukkit.jar:git-Bukkit-d27e6d0]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.jav
a:62) ~[craftbukkit.jar:git-Bukkit-d27e6d0]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.j
ava:501) [craftbukkit.jar:git-Bukkit-d27e6d0]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.j
ava:486) [craftbukkit.jar:git-Bukkit-d27e6d0]
        at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java
:1564) [craftbukkit.jar:git-Bukkit-d27e6d0]
        at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:31)
 [craftbukkit.jar:git-Bukkit-d27e6d0]
        at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:9)
[craftbukkit.jar:git-Bukkit-d27e6d0]
        at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:1
3) [craftbukkit.jar:git-Bukkit-d27e6d0]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [
?:1.8.0_51]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_51]
        at net.minecraft.server.v1_8_R3.SystemUtils.a(SystemUtils.java:19) [craf
tbukkit.jar:git-Bukkit-d27e6d0]
        at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:6
72) [craftbukkit.jar:git-Bukkit-d27e6d0]
        at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:3
35) [craftbukkit.jar:git-Bukkit-d27e6d0]
        at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:6
28) [craftbukkit.jar:git-Bukkit-d27e6d0]
        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java
:536) [craftbukkit.jar:git-Bukkit-d27e6d0]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_51]
Caused by: ru.tehkode.permissions.exceptions.PermissionsNotAvailable: Permission
s manager is not accessable. Is the PermissionsEx plugin enabled?
        at ru.tehkode.permissions.bukkit.PermissionsEx.getPermissionManager(Perm
issionsEx.java:405) ~[?:?]
        at net.milkbowl.vault.permission.plugins.Permission_PermissionsEx.getUse
r(Permission_PermissionsEx.java:243) ~[?:?]
        at net.milkbowl.vault.permission.plugins.Permission_PermissionsEx.player
Add(Permission_PermissionsEx.java:168) ~[?:?]
        at net.milkbowl.vault.permission.Permission.playerAdd(Permission.java:20
0) ~[?:?]
        at com.sevlon.PurchaseCommands.PurchaseCommands.inventoryclick(PurchaseC
ommands.java:118) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0
_51]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0
_51]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1
.8.0_51]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_51]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:300) ~[craftbukkit.jar:git-Bukkit-d27e6d0]
        ... 15 more