I don't know why, because Ning has not figured it out yet, but if you get "Our apologies" or a "500 Error" it's a problem with the Ning platform today. They say it will be fixed by 10AM PST but I haven't seen evidence of that.
“The difference between an amateur and a professional is in their habits. An amateur has amateur habits. A professional has professional habits. We can never free ourselves from habit. But we can replace bad habits with good ones.”