Ip-Check error

java.lang.NullPointerException
	at net.risenphoenix.jnk.ipcheck.Report.execute(Report.java:60)
	at net.risenphoenix.jnk.ipcheck.commands.CmdCheck.execute(CmdCheck.java:12)
	at net.risenphoenix.jnk.ipcheck.IPcheck.onCommand(IPcheck.java:182)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:189)
	at org.bukkit.craftbukkit.v1_5_R3.CraftServer.dispatchCommand(CraftServer.java:552)
	at net.minecraft.server.PlayerConnection.handleCommand(PlayerConnection.java:986)
	at net.minecraft.server.PlayerConnection.chat(PlayerConnection.java:902)
	at net.minecraft.server.PlayerConnection.a(PlayerConnection.java:847)
	at net.minecraft.server.Packet3Chat.handle(Packet3Chat.java:44)
	at org.spigotmc.netty.NettyNetworkManager.b(NettyNetworkManager.java:200)
	at net.minecraft.server.PlayerConnection.d(PlayerConnection.java:116)
	at net.minecraft.server.ServerConnection.b(SourceFile:35)
	at org.spigotmc.MultiplexingServerConnection.b(MultiplexingServerConnection.java:73)
	at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:590)
	at net.minecraft.server.DedicatedServer.r(DedicatedServer.java:227)
	at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:477)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:409)
	at net.minecraft.server.ThreadServerApplication.run(SourceFile:573)

Only happens for one player what should i do