Can't save a file into my cloud documents. Only offers the computer

When I try to save it used to offer both save to computer or save to cloud options, but when I tried to click the Cloud option. The box would disappear and reappear. Now it's not even doing that much. I can continue to send completed files onto my harddrive, but I want to keep a Master Copy that I can edit on a Cloud Doc so I can walk away and return to a project at my leisure. I looked into it and apparently I was following all the right steps, so I have no idea what's wrong. This is so frustrating because I want to work on my projects without losing my progress!