factions internal server error.

[bigb99100]

20:28:21 [iNFO] [Factions v1.7.5_dev] Reset faction data (invalid faction) for p

layer bigb99100

20:28:21 [sEVERE] null

org.bukkit.command.CommandException: Unhandled exception executing command 'f' i

n plugin Factions v1.7.5_dev

at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)

at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:18

6)

at org.bukkit.craftbukkit.v1_4_R1.CraftServer.dispatchCommand(CraftServe

r.java:534)

at iv.d(NetServerHandler.java:1390)

at iv.chat(NetServerHandler.java:1258)

at iv.a(NetServerHandler.java:1182)

at cu.a(Packet3Chat.java:59)

at cg.b(TcpConnection.java:467)

at iv.d(NetServerHandler.java:220)

at iw.b(NetworkListenThread.java:57)

at ht.b(DedicatedServerListenThread.java:34)

at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:981)

at ho.r(DedicatedServer.java:309)

at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:857)

at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:744)

at fy.run(ThreadMinecraftServer.java:16)

Caused by: java.lang.NullPointerException

at com.massivecraft.factions.FPlayer.getRelationToLocation(Unknown Sourc

e)

at com.massivecraft.factions.listeners.FactionsPlayerListener.preventCom

mand(Unknown Source)

at com.massivecraft.factions.P.handleCommand(Unknown Source)

at com.massivecraft.factions.P.onCommand(Unknown Source)

at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)

... 15 more

that's my error. please help. i host a small server on a local machine and players are getting mad.