Помогите Пропадают продавцы после перезагрузки

Когда пишу citizen save
выдаёт этот warn
Версия spigot 1.12.2


20.11 07:25:05 [Server] WARN at net.minecraft.server.v1_12_R1.PlayerConnectionUtils$1.run(SourceFile:13)
20.11 07:25:05 [Server] WARN at net.minecraft.server.v1_12_R1.PacketPlayInChat.a(PacketPlayInChat.java:1)
20.11 07:25:05 [Server] WARN at net.minecraft.server.v1_12_R1.PacketPlayInChat.a(PacketPlayInChat.java:45)
20.11 07:25:05 [Server] WARN at net.minecraft.server.v1_12_R1.PlayerConnection.a(PlayerConnection.java:1227)
20.11 07:25:05 [Server] WARN at net.minecraft.server.v1_12_R1.PlayerConnection.handleCommand(PlayerConnection.java:1392)
20.11 07:25:05 [Server] WARN at org.bukkit.craftbukkit.v1_12_R1.CraftServer.dispatchCommand(CraftServer.java:651)
20.11 07:25:05 [Server] WARN at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141)
20.11 07:25:05 [Server] WARN at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
20.11 07:25:05 [Server] WARN at net.citizensnpcs.Citizens.onCommand(Citizens.java:237)
20.11 07:25:05 [Server] WARN at net.citizensnpcs.api.command.CommandManager.executeSafe(CommandManager.java:175)
20.11 07:25:05 [Server] WARN at net.citizensnpcs.api.command.CommandManager.execute(CommandManager.java:87)
20.11 07:25:05 [Server] WARN at net.citizensnpcs.api.command.CommandManager.executeMethod(CommandManager.java:152)
20.11 07:25:05 [Server] WARN at java.lang.reflect.Method.invoke(Unknown Source)
20.11 07:25:05 [Server] WARN at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
20.11 07:25:05 [Server] WARN at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
20.11 07:25:05 [Server] WARN at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
20.11 07:25:05 [Server] WARN at net.citizensnpcs.commands.AdminCommands.save(AdminCommands.java:64)
20.11 07:25:05 [Server] WARN at net.citizensnpcs.Citizens.storeNPCs(Citizens.java:454)
20.11 07:25:05 [Server] WARN at net.citizensnpcs.Citizens.storeNPCs(Citizens.java:449)
20.11 07:25:05 [Server] WARN at net.citizensnpcs.api.npc.SimpleNPCDataStore.store(SimpleNPCDataStore.java:80)
20.11 07:25:05 [Server] WARN at net.citizensnpcs.npc.CitizensNPC.save(CitizensNPC.java:150)
20.11 07:25:05 [Server] WARN at net.citizensnpcs.api.npc.AbstractNPC.save(AbstractNPC.java:341)
20.11 07:25:05 [Server] WARN at net.dandielo.citizens.traders_v3.traits.TraderTrait.save(TraderTrait.java:70)
20.11 07:25:05 [Server] WARN at net.dandielo.citizens.traders_v3.traders.stock.StockTrader.save(StockTrader.java:121)
20.11 07:25:05 [Server] WARN at net.dandielo.citizens.traders_v3.traders.stock.StockItem.toString(StockItem.java:87)
20.11 07:25:05 [Server] WARN at net.dandielo.core.items.dItem.serialize(dItem.java:115)
20.11 07:25:05 [Server] WARN at net.dandielo.core.items.serialize.ItemAttribute.toString(ItemAttribute.java:109)
20.11 07:25:05 [Server] WARN at net.dandielo.core.items.serialize.core.LeatherColor.serialize(LeatherColor.java:41)
20.11 07:25:05 [Server] WARN java.lang.NullPointerException