17:32:03 [SEVERE] Could not pass event VehicleMoveEvent to MinecartExtra
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:304)
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
        at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:30)
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:460)
        at net.minecraft.server.EntityMinecart.F_(EntityMinecart.java:604)
        at net.minecraft.server.World.entityJoinedWorld(World.java:1262)
        at net.minecraft.server.WorldServer.entityJoinedWorld(WorldServer.java:106)
        at net.minecraft.server.World.playerJoinedWorld(World.java:1244)
        at net.minecraft.server.World.tickEntities(World.java:1151)
        at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:558)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:459)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)
Caused by: java.util.ConcurrentModificationException
        at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793)
        at java.util.HashMap$KeyIterator.next(HashMap.java:828)
        at me.ChrisvA.MinecartExtra.MinecartExtra.cleanup(MinecartExtra.java:198)
        at me.ChrisvA.MinecartExtra.MinecartExtra.StorageMinecartMove(MinecartExtra.java:131)
        at me.ChrisvA.MinecartExtra.MinecartExtraVehicleListener.onVehicleMove(MinecartExtraVehicleListener.java:59)
        at sun.reflect.GeneratedMethodAccessor38.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302)
        ... 11 more