I was told in a phone call from Verizon Tech Support that they know there is a problem, a recent Windows update broke Verizon Messages for Windows 10.  A team is "working on it", but, I was told that Verizon no longer supports Verizon Messages for Windows 10.  The only way Verizon supports for a customer to access text messages while using Windows 10 is to use a browser to visit the My Verizon webpage and see and send texts there.

This is clearly not OK, but I can't find any real support at Verizon to get the app working again.