Adobe Digital Editions has suddenly stopped working

I have been using Adobe Digital Editions 4.5.1 on Windows 10 successfully until yesterday, when it suddenly stopped working. When I click on the desktop icon for it, an icon for ADE appears in the taskbar, blinking. When I hover over that icon, a thumbnail of the "My Digital Editions" library appears. However, when I click on the icon in the taskbar, the My Digital Editions library opens in a window on the desktop for a split second only, then disappears. I have tried uninstalling and reinstalling it, but it still won't open. I also, per instructions elsewhere in this forum, backed the previous library up, deleted the My Digital Editions folder from my computer, removed and then reinstalled Digital Media Edition. It still does not open.

Can you advise how to fix this?

Frank