@Steven Schlossman - I have encountered this when a registration does not meet a certain criteria. It is a default message. When the capacity of 50 is reached, perhaps THAT is when everyone is getting the default message. Have you tried digging into the Language Management side and changing the default message? I would think that once capacity is reached Registration closes, but if there is waitlist enabled or some other option enabled that keeps registration open although the capacity has been reached, perhaps changing the default message to something like, "We're sorry, our event registration capacity has been reached" might work?