Photos app wants to upload my library to iCloud once again After I upgraded to OS X EL Capitan, I need to turn iCloud Photo Library once again on my Macbook Pro, but once I tap on iCloud Photo library checkbox the Photos a[[ wants to upload my images once again. But every image now exist in my iCloud Photo Library. I do not want to upload this once again.

I had 5GB, my library was 25GB, So I bought a new plan with 50GB for 1$ per month. Now It wants to upload 25GB once again, but there is not enough space, so it redirect me to upgrade my iCloud storage plan to 200GB. I do not want that. All I need is to turn iCloud Photo Library on my mac once again. Is it possible? How can I do that?

What does it mean?
Had same problem, steps to start syncing again:


open system preferences
iCloud
control...
locate your Media data and click delete
it will be marked as deleted and available for download during 30 days, free space will show all of your space
go to Photos
Settings...
click [x] iCloud
now it will turn on
go back to System preferences
iCloud
Control...
locate your Media data and click Cancel Delete
be happy
let me know if that helped ;)