@Sean433
So this may well have been blocked because the guest was trying to make a last minute booking (if it was indeed last minute) for a whole property and she was under 25. Seems stupid to me to have such a blanket policy, where guests who are staying for a month with their parents cannot book! Was she local?
Also, I can only guess that the reason Airbnb is telling the guest that they are blocking the booking is because it's for their own safety is that they would have a lot of outraged guests if they told people, "We are not letting you book this property because you are under 25 and we don't trust you not to throw a party and trash the place."
It is also in violation of their own policy about not discriminating based on age.