ACCESS DENIED for unmodified Adobe PDF file from same directory with new name

I think I have a solution. Win10 must have recently changed its Settings for Acrobat access to the Controlled Folders under its Virus and Threat Protection settings. (Settings - Security (advanced) - Virus & threat protection settings - Manage settings - Manage Controlled Folder access - Allow an app through Controlled folder access - Add an allowed app). Once I added Adobe and the associated services that had recently been blocked, I could save without the error message.