globalmarket error

[20:14:44 ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'market' in plugin GlobalMarket v1.3.0-SNAPSHOT
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot.jar:git-Spigot-1178]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:192) ~[spigot.jar:git-Spigot-1178]
        at org.bukkit.craftbukkit.v1_7_R1.CraftServer.dispatchCommand(CraftServer.java:546) ~[spigot.jar:git-Spigot-1178]
        at net.minecraft.server.v1_7_R1.PlayerConnection.handleCommand(PlayerConnection.java:938) [spigot.jar:git-Spigot-1178]
        at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:813) [spigot.jar:git-Spigot-1178]
        at net.minecraft.server.v1_7_R1.PacketPlayInChat.a(PacketPlayInChat.java:28) [spigot.jar:git-Spigot-1178]
        at net.minecraft.server.v1_7_R1.PacketPlayInChat.handle(PacketPlayInChat.java:65) [spigot.jar:git-Spigot-1178]
        at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146) [spigot.jar:git-Spigot-1178]
        at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [spigot.jar:git-Spigot-1178]
        at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:647) [spigot.jar:git-Spigot-1178]
        at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:259) [spigot.jar:git-Spigot-1178]
        at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:530) [spigot.jar:git-Spigot-1178]
        at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:442) [spigot.jar:git-Spigot-1178]
        at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [spigot.jar:git-Spigot-1178]
Caused by: java.lang.NullPointerException
        at com.survivorserver.GlobalMarket.MarketStorage.storeItem(MarketStorage.java:344) ~[?:?]
        at com.survivorserver.GlobalMarket.MarketStorage.createListing(MarketStorage.java:364) ~[?:?]
        at com.survivorserver.GlobalMarket.Command.CreateCommand.onCommand(CreateCommand.java:147) ~[?:?]
        at com.survivorserver.GlobalMarket.Command.MarketCommand.onCommand(MarketCommand.java:50) ~[?:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot.jar:git-Spigot-1178]
        ... 13 more