Win10 Message+ v3.0.0 now in Microsoft Store
Champion - Level 3

As of 8/20/2021, there is a new Verizon Messages app for Windows 10 in the Microsoft Store, 

as reported in the 'Unexpected Error'  thread. 

WooHoo!!  but wait.  When installing, it doesn't like the 8/18/2021 Message+ app on my primary device, saying it is 'out-of-date' and needs to be updated.  There is NO newer update available in the Play Store.  Unstalling (with reservations) Message+ on my moto z4 dropped from v8.0.6 to v6.9.8 and the v3.0.0 Win10 Message+ app installed 'successfully'.  There is no SYNC option in the new Win10 v3.0.0 and no messages appear received after 8/12/2021.  Reporting as bugs in the app.

...Just another VZW customer...trying to offer some assistance...