I'm having an annoying problem with the Photos app on my mac. Trying to make a photo book, I have uploaded a load of photos and started formatting them then it won't let me back in.
A search around has found this chap who is having the same problem.
https://discussions.apple.com/message/29374333#29374333
Any suggestions? I don't often run out of ideas like this!
OSX El Capitan,
Photos Version 1.1,
I have the full Icloud photo backup account.