Clients Crashing.

Players on PlungeMC's Prison are crashing with the following error;
---- Minecraft Crash Report ----
// I blame Dinnerbone.

Time: 15/10/14 19:46
Description: Unexpected error

java.lang.IllegalStateException: Player is either on another team or not on any team. Cannot remove from team 'CTAGS32992595'.
at bac.a(SourceFile:206)
at bjb.a(SourceFile:1168)
at id.a(SourceFile:100)
at id.a(SourceFile:12)
at ej.a(SourceFile:174)
at bje.e(SourceFile:212)
at bao.p(SourceFile:1306)
at bao.ak(SourceFile:774)
at bao.f(SourceFile:728)
at net.minecraft.client.main.Main.main(SourceFile:148)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:134)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
I'm only a Moderator on that server and want to know, my guess is error "'CTAGS32992595'." referring to Coloured Name Tags?

 

java.lang.IllegalStateException: Player is either on another team or not on any team. Cannot remove from team 'CTAGS32992595'.

Might be an error with how scoreboards are setup and how the client is receiving it. Scoreboards are the only thing that has teams in default MC.