iCloud Drive needs to finish updating before continuing with sign out
While working with iCloud Drive somehow, can't remember what, all of my many Desktop files disappeared. I was able to get them back on the Desktop again but all folders show the "down cloud" icon, while single files such as jpegs do not. When I open a folder and click on a file it downloads and the "down cloud" icon disappears for that file. After doing that for all files in that folder that icon disappears for that folder, so it must be that all those files are safely back on my iMac. However I still have many folders still showing the "down cloud" icon.
During this time, several days now, I'm getting the window with message stating "iCloud Drive needs to finish updating before continuing with sign out." and spinning gear. The progress bar is complete and the status is "Finishing" I have 3 options: 1. keep waiting 2. Cancel 3. Stop Updating and Continue. What happens with each of them? I'm running 10.12.6 Sierra on an iMac.
iMac Line (2012 and Later)