If I go to mailings->draft, my new mailing is listed there. If I then click "continue", it goes to the same blank screen. If I try using mailings->new mailing, again the same blank screen, and a new draft mailing that I can't edit. This problem seems to have come up since I updated from 4.7.20 to 4.7.21 (updated 2 weeks ago, but this is the first new mailing we're trying to create since then). If more information is needed in order to reply, please tell me how/where to find it.