Hi, I got the same problem, more or less…
At home, the MyCloud is already set up with WD Sync (Windows 10 PC), but when I try to connect to it from the PC at work (Windows 7 Ultimate PC), I got the same problem as described above.
I can login and select the MyCloud, But it shows me “The underlying connection was closed: An unexpected error occured on a send”. I have to select my drive, again. This happens all the time, so I can’t proceed to the next steps.
Am I doing something wrong? Or are there some settings on my Windows 7 PC that I have to change, like Firewall or something?