Apple Photos Shared Albums on OS X are not updating
I created a new shared album on one computer. I can see that album on my iOS devices, but not on my other computer (all of them are on the same iCloud account). Quitting and restarting Apple Photos doesn't help. How do I get Apple Photos to see the updates?
Solution 1:
Quit Apple Photos. Now run Activity Monitor, look for Photos Agent, and kill it by selecting and clicking the X at the top left.
Now, start Apple Photos again. This will restart Photos Agent, and after a minute, you should see your updated shared albums.