just had this error as seen in the screenshot. Dropbox then went ahead and restarted itself and it works, but posting this here just in case.
Windows: windows 10, 2004
PC: Lenovo T450
P.S.: It's not possible to find an actual support email/chat feature. don't think it's the best way to have to post in a community forum where there is not even a subforum for the Dropbox app or bug reports.