icloud photo sync iphone

i have multiple apple devices. to date, i previously had photos, macbook, and iphone backups on external hard drives. i just synced to icloud from macbook for the first time (hold the comments for another time). now, when i try to turn on icloud photos on iphone, a message appears asking if i want to remove the photos from the phone; i click yes; it gives a message saying try again later. anyone experience this? i am not finding much literature out there on the web about this issue. i have tried signing out for each device, restarting, etc. to no avail.