You need to sign on, on your PC
go to your control panel or User panel the go to miscellaneous and you have to delete some of your older pictures. Your only allowed so many pics. I had the same problem, I deleted old pictures then just became a supporting member. Here's a picture.
Did you try to close out the app and restart it?
"When creating an aqua scape, strive for the beauty of imperfection, as its art and there is no wrong or right, it's left open for interpretation" James Findley