Short summary: I've had a OneDrive for Business folder shared with me, which I can access perfectly fine through the web interface, but when I attempt to "sync" locally with my machine, I eventually get a "We can't connect to the specified SharePoint site..." after being asked for my Microsoft Account credentials three times.
Got "we can't connect to the specified SharePoint site" If I attempt to "Sync Now", after clicking on 'Sync Now'.