Unable to make certain classes

I was trying to make a halfling paladin a while back and no matter what name I chose, it simply wouldn't let me make one. I ended up giving up and making something else.

Now I'm trying to make a Gnome Shadow Knight and no matter what name I pick, it will not let me create one. I thought maybe it was the name, but sure enough I can make a wizard or an enchanter with these names, just fine. As soon as I try to make a shadowknight with any of the 50 or so names I've tested, it won't let me. But it's not a timed out name thing either as I can go recreate the wizard with one of these names.

Anyone have any idea what's going on?