[04:33:59] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'ah' in plugin AuctionHouse v1.0
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot.jar:git-PaperSpigot-1f7d532]
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:181) ~[spigot.jar:git-PaperSpigot-1f7d532]
	at org.bukkit.craftbukkit.v1_7_R4.CraftServer.dispatchCommand(CraftServer.java:765) ~[spigot.jar:git-PaperSpigot-1f7d532]
	at net.minecraft.server.v1_7_R4.PlayerConnection.handleCommand(PlayerConnection.java:1047) [spigot.jar:git-PaperSpigot-1f7d532]
	at net.minecraft.server.v1_7_R4.PlayerConnection.a(PlayerConnection.java:884) [spigot.jar:git-PaperSpigot-1f7d532]
	at net.minecraft.server.v1_7_R4.PacketPlayInChat.a(PacketPlayInChat.java:28) [spigot.jar:git-PaperSpigot-1f7d532]
	at net.minecraft.server.v1_7_R4.PacketPlayInChat.handle(PacketPlayInChat.java:65) [spigot.jar:git-PaperSpigot-1f7d532]
	at net.minecraft.server.v1_7_R4.NetworkManager.a(NetworkManager.java:189) [spigot.jar:git-PaperSpigot-1f7d532]
	at net.minecraft.server.v1_7_R4.ServerConnection.c(ServerConnection.java:81) [spigot.jar:git-PaperSpigot-1f7d532]
	at net.minecraft.server.v1_7_R4.MinecraftServer.v(MinecraftServer.java:795) [spigot.jar:git-PaperSpigot-1f7d532]
	at net.minecraft.server.v1_7_R4.DedicatedServer.v(DedicatedServer.java:307) [spigot.jar:git-PaperSpigot-1f7d532]
	at net.minecraft.server.v1_7_R4.MinecraftServer.u(MinecraftServer.java:643) [spigot.jar:git-PaperSpigot-1f7d532]
	at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java:549) [spigot.jar:git-PaperSpigot-1f7d532]
	at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:628) [spigot.jar:git-PaperSpigot-1f7d532]
Caused by: java.lang.SecurityException: sealing violation: package com.google.common.io is sealed
	at java.net.URLClassLoader.getAndVerifyPackage(URLClassLoader.java:399) ~[?:1.8.0_66-internal]
	at java.net.URLClassLoader.definePackageInternal(URLClassLoader.java:419) ~[?:1.8.0_66-internal]
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:451) ~[?:1.8.0_66-internal]
	at java.net.URLClassLoader.access$100(URLClassLoader.java:73) ~[?:1.8.0_66-internal]
	at java.net.URLClassLoader$1.run(URLClassLoader.java:368) ~[?:1.8.0_66-internal]
	at java.net.URLClassLoader$1.run(URLClassLoader.java:362) ~[?:1.8.0_66-internal]
	at java.security.AccessController.doPrivileged(Native Method) ~[?:1.8.0_66-internal]
	at java.net.URLClassLoader.findClass(URLClassLoader.java:361) ~[?:1.8.0_66-internal]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:101) ~[spigot.jar:git-PaperSpigot-1f7d532]
	at org.bukkit.plugin.java.JavaPluginLoader.getClassByName(JavaPluginLoader.java:193) ~[spigot.jar:git-PaperSpigot-1f7d532]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:97) ~[spigot.jar:git-PaperSpigot-1f7d532]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86) ~[spigot.jar:git-PaperSpigot-1f7d532]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_66-internal]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_66-internal]
	at net.cfilatov.auctionhouse.data.DataHandler.serializeItemStack(DataHandler.java:225) ~[?:?]
	at net.cfilatov.auctionhouse.data.DataHandler.saveListing(DataHandler.java:124) ~[?:?]
	at net.cfilatov.auctionhouse.controller.Controller.sell(Controller.java:46) ~[?:?]
	at net.cfilatov.auctionhouse.commands.CommandHandler.handleAuctionSell(CommandHandler.java:75) ~[?:?]
	at net.cfilatov.auctionhouse.commands.CommandHandler.onCommand(CommandHandler.java:34) ~[?:?]
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot.jar:git-PaperSpigot-1f7d532]
	... 13 more