I think I had this happen a couple of times and eventually figured it out. I think you can't print from the "Notation" page or Images, but... scroll down... scroll down... keep scrolling.... eventually you'll see a button that says PRINT NOTATION and that one works. I'm not sure if it is there for all of them, but that was what worked for me when I had the problem you describe.
It takes as long as it takes unless you quit - then it takes forever and you will never get there.