If you are still having an issue with the PC App, please uninstall the version on your PC.
Then, install the app from the 'download desktop app' link on the Verizon page as illustrated on this USER GUIDE.
If you continue to have issues, just let us know.
I did as instructed, but the desktop app did not sync, even after I let it try overnight. I was able to get the app from the Windows Store to work;however, the Windows Store app does not appear to give notifications when messages arrive.