I've been using Dropbox with Chrome for many years. Today, however, Chrome shows blank or nearly blank pages. I tried clearing the cache (for "All time", Browsing history, Download history, Cookies and other site data, Cached images and files), rebooting, all no joy. If I open Chrome in Incognito mode, it works. It works also with Microsoft Edge and Firefox.
I repeated the Clear browsing data option, this time for All Time, and with all options checked. I closed the browser, waited 10 seconds and tried again. No joy.
One additional symptom to report: On the "All files" page in Dropbox, I see light blue or grey background where the folders and files should be. If I highlight these with the mouse, I can see the text reads: "My Files" and each row below shows "The file name", "Type".