Stop running, disk unreadable

I run Recuva on a working external 1TB HDD on my Win10 64bit system to recover some deleted file but couldn't find them after running in normal mode. Then I start a deep scan and found many files but before I can do any recovery, Recuva stopped working.

My HDD is now unreadable - I can't access it anymore. What is the problem and how to resolve this? Thanks

Restarting the computer and/or powering down and restarting the drive may allow access to it again; you might also try connecting it to a different USB port. When an external hard drive is unable to be accessed that most commonly means that the drive housing's electronics have 'locked up'.

(Much like a computer, a peripheral's electronics can also 'hang' or stop responding and need a restart in order to start working again.)

Unfortunately, if that doesn't take care of the matter, that could indicate that the drive itself has crashed, or (slightly more preferably) the housing's electronics have failed, which could well be what then caused Recuva to stop responding as well (when the drive stopped communicating with the computer unexpectedly). At that point, it might be best to contact the manufacturer of the drive to see what options are available for repairing it, if any.

Try to access a 2-year-old WD MY BOOK ESSENTIAL, but failed with an error saying 'the disk structure is corrupted and unreadable.' What's the matter? This issue is very frustrating as all my important data is stored on this drive. Anyone can show me instructions on how to recover data when the disk structure is corrupted and unreadable.