>>The problem: The system will not allow me to see or select local files & folders to sync to Dropbox. Below is a screenshot.
>> The backstory: My Dropbox local app seemed to be having issues for a long while.
The simplest solution (IMO) was to reset, so I renamed the e:\Dropbox directory to e:\OLD DROPBOX, and I moved the same files online into a single Dropbox ..\Old files before 202209. check to make sure all files were there. Then I deleted the local Dropbox app. Then reinstalled & rebooted.
Dropbox didn't like that I renamed its folder, but I got that worked out. Now the Dropbox app is seeing its new folder at e:\Dropbox.

Those two folders are the only to items in e:\Dropbox