When I added AuctionGUI+ and restarted it, it was not working due to this error. It says its not up to date but it is the latest version which is 1.2.0. I hope someone can fix this error. I use spigot 1.7.9 r02.

[00:35:25 INFO]: [AuctionGUIPlus] Enabling AuctionGUIPlus v1.2.0
[00:35:25 ERROR]: Error occurred while enabling AuctionGUIPlus v1.2.0 (Is it up to date?)
java.lang.IllegalArgumentException
at net.brcdev.auctiongui.util.ItemUtil.loadItemStackFromConfig(ItemUtil.java:56) ~[?:?]
at net.brcdev.auctiongui.object.settings.MenuSettings.load(MenuSettings.java:35) ~[?:?]
at net.brcdev.auctiongui.object.settings.MenuSettings.<init>(MenuSettings.java:27) ~[?:?]
at net.brcdev.auctiongui.config.SettingsMenu.load(SettingsMenu.java:50) ~[?:?]
at net.brcdev.auctiongui.config.SettingsMenu.setConfig(SettingsMenu.java:31) ~[?:?]
at net.brcdev.auctiongui.AuctionGuiPlugin.onEnable(AuctionGuiPlugin.java:118) ~[?:?]
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:316) ~[server.jar:git-Spigot-1.7.9-R0.2-208-ge0f2e95]
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:332) [server.jar:git-Spigot-1.7.9-R0.2-208-ge0f2e95]
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:412) [server.jar:git-Spigot-1.7.9-R0.2-208-ge0f2e95]
at org.bukkit.craftbukkit.v1_7_R4.CraftServer.loadPlugin(CraftServer.java:476) [server.jar:git-Spigot-1.7.9-R0.2-208-ge0f2e95]
at org.bukkit.craftbukkit.v1_7_R4.CraftServer.enablePlugins(CraftServer.java:394) [server.jar:git-Spigot-1.7.9-R0.2-208-ge0f2e95]
at net.minecraft.server.v1_7_R4.MinecraftServer.n(MinecraftServer.java:360) [server.jar:git-Spigot-1.7.9-R0.2-208-ge0f2e95]
at net.minecraft.server.v1_7_R4.MinecraftServer.g(MinecraftServer.java:334) [server.jar:git-Spigot-1.7.9-R0.2-208-ge0f2e95]
at net.minecraft.server.v1_7_R4.MinecraftServer.a(MinecraftServer.java:290) [server.jar:git-Spigot-1.7.9-R0.2-208-ge0f2e95]
at net.minecraft.server.v1_7_R4.DedicatedServer.init(DedicatedServer.java:210) [server.jar:git-Spigot-1.7.9-R0.2-208-ge0f2e95]
at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java:458) [server.jar:git-Spigot-1.7.9-R0.2-208-ge0f2e95]
at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:628) [server.jar:git-Spigot-1.7.9-R0.2-208-ge0f2e95]