After a considerable amount of time checking my settings ,sample rate, channels etc. because Audacity was unable to open sound device and advised checking these settings I found that the problem lies in the Privacy settings in Windows 10 - you need to “Enable apps to access the microphone”, even though you might not be using a microphone but Line-in, as in my case. It might be helpful if this advice appeared in the error message as I could not find a solution in the forum for this precise problem.
We created a Sticky topic for this at the Top of the Windows section
And I’ve just added that advice to the alpha Manual FAQ for the upcoming 2.3.1 release.: