Today, BD 2018 continuously attempted to start following continuously experiencing a "fatal error." (auto messages sent to BD).
So, I uninstalled, and reinstalled BD Family. The reinstall process worked (download, install, scan, login to account) up to the point shown in the attached screen capture. There it appears to have hung. There is no indication of progress.
Running fully up to date Win 10 Version 1709 (build 6299.125), Windows Defender protections are turned off. No other applications were in progress (are in progress except this browser session).
Sorry, error -200 when attempting to upload 1.3 Mb *.PNG file multiple times. Groan. Hard to have confidence in a product that can't even do to the simple stuff.