Sudden onset of "Your input can't be opened: ... unable to open MRL"

ME?: Casual user of VLC many years.
Until two weeks ago, I was heavily using VLC to view drone mp4 files and extracting still images therefrom.
The latest MS update to my computer was 4 days ago, after the loss of functionality.
I don't know what changed, I didn't do anything.
These files went from the Mavic chip to my computer, no network involved, no restrictions.
Files from the Mavic play perfectly well on my junk HP laptop and on other people's computers.

A search of your forum finds surprisingly few mentions of this problem.