Can't invite others to iCloud shared photo albums... "Invite People" button missing Title says it. There is no "Invite People" link/button...

What setting do I need to change? Yes, I've got iCloud setup. Do I have to upgrade to the new iCloud storage? 

Edit: more details: iPhone 5s. iOS 8. I think it's maybe because I have zero contacts in iCloud?

Edit: more details: When I create a new shared album, everything seems fine. I can add people to share with, or even delete the album. But the original album that prompted me to ask this question does not allow me to either add people to share with, nor does it allow me to delete the album. Something is special about it. Should all albums be equivalent, or is there a special use case for special albums that can't be shared nor deleted? The album name is "Family". I suppose the answer to my conundrum is that this album is specifically tied to people I add to my "Family". Not sure exactly how to do this but I suppose they also have to have iDevices.
I had this problem on an albums other than the Family album on a MacBook Air. It turned out to that the "To:" line was hidden whenever Photos.app was running on an external display. When I put Photos back on the laptop screen the control would re-appear.