error

[00:24:46] [Server thread/INFO]: Majdd issued server command: /bookgui
[00:24:47] [Server thread/INFO]: Majdd issued server command: /bookgui accept
[00:24:47] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'bookgui' in plugin EazyNick v1.229
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:47) ~[minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:149) ~[minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.craftbukkit.v1_14_R1.CraftServer.dispatchCommand(CraftServer.java:710) ~[minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.PlayerConnection.handleCommand(PlayerConnection.java:1641) ~[minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.PlayerConnection.a(PlayerConnection.java:1481) ~[minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.PacketPlayInChat.a(PacketPlayInChat.java:47) ~[minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.PacketPlayInChat.a(PacketPlayInChat.java:1) ~[minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:19) ~[minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.TickTask.run(SourceFile:18) [minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.IAsyncTaskHandler.executeTask(SourceFile:144) [minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23) [minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.IAsyncTaskHandler.executeNext(SourceFile:118) [minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.MinecraftServer.aX(MinecraftServer.java:910) [minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.MinecraftServer.executeNext(MinecraftServer.java:903) [minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.IAsyncTaskHandler.executeAll(SourceFile:103) [minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.MinecraftServer.sleepForTick(MinecraftServer.java:886) [minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.MinecraftServer.run(MinecraftServer.java:820) [minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_231]
Caused by: java.lang.IllegalArgumentException: Cannot translate null text
        at org.apache.commons.lang.Validate.notNull(Validate.java:192) ~[minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.ChatColor.translateAlternateColorCodes(ChatColor.java:354) ~[minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        at net.dev.nickplugin.utils.BookGUIFileUtils.getConfigString(BookGUIFileUtils.java:176) ~[?:?]
        at net.dev.nickplugin.commands.BookGUICommand.onCommand(BookGUICommand.java:58) ~[?:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45) ~[minecraft_server.jar:git-Spigot-9de398a-9c887d4]
        ... 17 more