Although a tongue-in-cheek suggestion, sadly it won't work. As we discovered in December, you have to print off the boarding pass at the moment you make the booking. Unlike other airlines, you can't come back later, access your booking, and print off the boarding pass the night before you head off or at the airport.
Or so it was for us.
Think it must have been as can only check in 15 days beforehand.
I had made the booking on a computer which wasn't linked to a printer. When I later wanted to print off the boarding pass I couldn't access the particular webpage containing the printable boarding pass. This meant that having access to a computer and printer didn't help and we were forced to pay for normal check-in despite having no bags!
Perhaps things will change with the new system, but somehow I doubt it...
I'm figuring you went back to the original page and tried to load the page and print from there.
What you were able to do is go onto the Ryanair website and check in and print boarding pass from there.