thank you my mobile data when i tether my macbook air has been massive you have told me what caused my problem the people at the genius bar at the apple shop could not work out how to fix my problem again thank you
You can also turn off the sync of desktop and documents on Sierra to iCloud, which I did - I keep videos on my desktop, I have about 100 GB of videos there. That would be a disaster to my iCloud storage plan if I sync'd them!