When updating to version 16.9 of the desktop connector it is common to get this error

You will want to be sure to check your desktop connector and take a screenshot to see all active projects you have selected
(you will have to re select and sync projects once this error is resolved)

for example:

once you have done this completely close the desktop connector

open up the file explorer and put this in the top bar

%UserProfile%/DC 

delete all contents in this folder

then re open desktop connector and select projects

source: https://help.autodesk.com/view/CONNECT/ENU/?guid=Cleanup_Bad_Drives