/chm blame bug

[riddle]

[11:52:39 INFO]: ridddle issued server command: /chm blame 10935
[11:52:39 ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'chm' in plugin Challenges v1.0.2
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot-1.7.9-dev.jar:git-Spigot-1465]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:180) ~[spigot-1.7.9-dev.jar:git-Spigot-1465]
        at org.bukkit.craftbukkit.v1_7_R3.CraftServer.dispatchCommand(CraftServer.java:728) ~[spigot-1.7.9-dev.jar:git-Spigot-1465]
        at net.minecraft.server.v1_7_R3.PlayerConnection.handleCommand(PlayerConnection.java:985) [spigot-1.7.9-dev.jar:git-Spigot-1465]
        at net.minecraft.server.v1_7_R3.PlayerConnection.a(PlayerConnection.java:830) [spigot-1.7.9-dev.jar:git-Spigot-1465]
        at net.minecraft.server.v1_7_R3.PacketPlayInChat.a(PacketPlayInChat.java:28) [spigot-1.7.9-dev.jar:git-Spigot-1465]
        at net.minecraft.server.v1_7_R3.PacketPlayInChat.handle(PacketPlayInChat.java:65) [spigot-1.7.9-dev.jar:git-Spigot-1465]
        at net.minecraft.server.v1_7_R3.NetworkManager.a(NetworkManager.java:180) [spigot-1.7.9-dev.jar:git-Spigot-1465]
        at net.minecraft.server.v1_7_R3.ServerConnection.c(ServerConnection.java:81) [spigot-1.7.9-dev.jar:git-Spigot-1465]
        at net.minecraft.server.v1_7_R3.MinecraftServer.v(MinecraftServer.java:713) [spigot-1.7.9-dev.jar:git-Spigot-1465]
        at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:283) [spigot-1.7.9-dev.jar:git-Spigot-1465]
        at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:576) [spigot-1.7.9-dev.jar:git-Spigot-1465]
        at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:482) [spigot-1.7.9-dev.jar:git-Spigot-1465]
        at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [spigot-1.7.9-dev.jar:git-Spigot-1465]
Caused by: java.lang.NullPointerException
        at java.util.regex.Matcher.appendReplacement(Matcher.java:758) ~[?:1.7.0_21]
        at java.util.regex.Matcher.replaceAll(Matcher.java:906) ~[?:1.7.0_21]
        at java.lang.String.replaceAll(String.java:2162) ~[?:1.7.0_21]
        at us.corenetwork.challenges.modcommands.HistoryCommand.getChallengeBlame(HistoryCommand.java:93) ~[?:?]
        at us.corenetwork.challenges.modcommands.BlameCommand.run(BlameCommand.java:32) ~[?:?]
        at us.corenetwork.challenges.modcommands.BaseModCommand.execute(BaseModCommand.java:42) ~[?:?]
        at us.corenetwork.challenges.Challenges.onCommand(Challenges.java:198) ~[?:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot-1.7.9-dev.jar:git-Spigot-1465]
        ... 13 more

This is for a challenge that has been claimed by a mod that wasn’t checked yet.