I've figured out how to solve the ubiquitous problem of Garmin Express failing to sync and/or recognize it's own products - i.e., Forerunner, etc. Resolution of this pesky problem requires only two steps:
1) Uninstall Garmin Express
2) Go back to using Garmin Training Center
Optional step:
3) Ask yourself out loud "What exactly was the purpose of Garmin Express in the first place?"