I've never found the lifetime map updater to work at all! Just sits there and never notifies me of anything. The way I've tended to do it is via MyGarmin. Click on the latest map and it installs something-or-other and the map downloads and installs. We have a new Europe map out officially soon, I believe so I'll probably try Garmin Express to download that and see how it goes.
I do find GE works well for installing latest firmware and gives me the option of installing the latest voice files, so I've nothing against it. I do however detest BaseCamp!
I have no idea is MyDashboard works! All I've ever seen on both my Garmin's over several PC's and different OS is the "Communicating with device - this should take a few seconds" screen for however long I let it try (an hour yesterday) before I give up. If the Garmin is out of warranty and you install firmware Garmin say you should have, surely it's down to Garmin to sort if their update bricks an out of warranty unit?