Bukkit

What steps will reproduce the problem?

Creating some shops

What is the expected output? What do you see instead?

If I tipe "/vshop save", I would expect [VS]>>>Saved!<<< only but I get the message: "An internal error occurrent while attemping to perform this command" too

What version of the product are you using?

Version 0.4d for CB 1.7.9 but I use Spigot 1.8.8

Do you have an error log of what happened?

This is the Error log:

[22:20:41 ERROR]: null

org.bukkit.command.CommandException: Unhandled exception executing command 'vshop' in plugin VillagerShop v0.4d

    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[server.jar:git-Spigot-76236cb-62a2169]

    at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[server.jar:git-Spigot-76236cb-62a2169]

    at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:641) ~[server.jar:git-Spigot-76236cb-62a2169]

    at net.minecraft.server.v1_8_R3.PlayerConnection.handleCommand(PlayerConnection.java:1162) [server.jar:git-Spigot-76236cb-62a2169]

    at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:997) [server.jar:git-Spigot-76236cb-62a2169]

    at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:45) [server.jar:git-Spigot-76236cb-62a2169]

    at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:1) [server.jar:git-Spigot-76236cb-62a2169]

    at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [server.jar:git-Spigot-76236cb-62a2169]

    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.7.0_10]

    at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source) [?:1.7.0_10]

    at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.7.0_10]

    at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [server.jar:git-Spigot-76236cb-62a2169]

    at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:715) [server.jar:git-Spigot-76236cb-62a2169]

    at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [server.jar:git-Spigot-76236cb-62a2169]

    at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654) [server.jar:git-Spigot-76236cb-62a2169]

    at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557) [server.jar:git-Spigot-76236cb-62a2169]

    at java.lang.Thread.run(Unknown Source) [?:1.7.0_10]

Caused by: java.lang.NullPointerException

    at net.bplaced.pririor.villagershop.VillagerShop.saveShops(VillagerShop.java:198) ~[?:?]

    at net.bplaced.pririor.villagershop.VillagerShop.onCommand(VillagerShop.java:430) ~[?:?]

    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[server.jar:git-Spigot-76236cb-62a2169]

    ... 16 more

Thank you for your help