10:39:16 [SEVERE] Could not pass event PlayerInteractEvent to eShop v1.5.2
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:30)
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:478)
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:463)
        at org.bukkit.craftbukkit.v1_6_R2.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:209)
        at org.bukkit.craftbukkit.v1_6_R2.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:179)
        at net.minecraft.server.v1_6_R2.PlayerConnection.a(PlayerConnection.java:1023)
        at net.minecraft.server.v1_6_R2.Packet18ArmAnimation.handle(SourceFile:41)
        at org.spigotmc.netty.NettyNetworkManager.b(NettyNetworkManager.java:235)
        at net.minecraft.server.v1_6_R2.PlayerConnection.e(PlayerConnection.java:118)
        at net.minecraft.server.v1_6_R2.ServerConnection.b(SourceFile:37)
        at org.spigotmc.netty.NettyServerConnection.b(NettyServerConnection.java:125)
        at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:592)
        at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:239)
        at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:481)
        at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:413)
        at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)
Caused by: java.lang.UnsupportedOperationException
        at java.util.AbstractList.add(AbstractList.java:148)
        at com.robbyduke.eshop.util.CreateShop.populate(CreateShop.java:37)
        at com.robbyduke.eshop.event.PlayerEvent.playerInteract(PlayerEvent.java:80)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        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)
        ... 17 more