Null Error while using /help

Hi there, I have a problem with using /help command:

Code:

[14:32:05 INFO]: Girion_ issued server command: /help[14:32:05 ERROR]: nullorg.bukkit.command.CommandException: Unhandled exception executing 'help' in org.bukkit.command.defaults.HelpCommand(help)at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:148) ~[minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:641) ~[minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at net.minecraft.server.v1_8_R3.PlayerConnection.handleCommand(PlayerConnection.java:1162) [minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:997) [minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:45) [minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:1) [minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_74]at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_74]at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:715) [minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654) [minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557) [minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at java.lang.Thread.run(Thread.java:745) [?:1.8.0_74]Caused by: java.lang.NullPointerExceptionat org.bukkit.help.IndexHelpTopic.getFullText(IndexHelpTopic.java:70) ~[minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at org.bukkit.command.defaults.HelpCommand.execute(HelpCommand.java:87) ~[minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[minecraft_server.jar:git-Spigot-e4d4710-e1ebe52]... 14 more

We found out it could be connected with Denizen plugin, no idea how (/help works if we delete the Denizen plugin).