iCloud Photo Sharing enabled but get error message every time
I have followed the directions to enable "iCloud Photo Sharing" although when I try to subscribe to a photo album that has been shared with me I get an error message that says I need to enable iCloud Photo Sharing. What am I doing wrong?
MacBook Pro (Retina, 13-inch, Late 2013), OS X Yosemite (10.10.3)