MyCloud unable to mount drive

I’m reposting my query as not getting far with a solution. For several days I have been unable to access data on my MyCloud 2TB netdrive and get the error ‘Failure to mount drive’. I have tried re-booting and 4 sec and 40 sec reset without success. Sometimes it has had a flashing white LED but now solid red LED. I have used it for several years with few problems with various routers (currently Virgin Hub3). I use Windows 10. Performing short and long system diagnostics tests results in ‘ OK’ but on the dashboard it shows 0kB free (which I doubt) and SCANNING as well as Critical in the diagnosis link (‘Content status - not mounted’).
WD support have sent me links to using SSH - but I have very wary of trying this as not sure what I am doing or which of the download listed is the most appropriate.

I would really appreciate more help with this problem as I am really uncomfortable following the link suggested as even the characters for the command line are not clear to me - see below

ls /
Is this first character a capital ‘I’ as in ‘Is’ or is it a lower case ‘l’ as in ‘line’ ?

Since there are warnings that the wrong command can destroy the data it is very scary - I am moderately competent with IT but by no means an expert and this is way out of my comfort zone.

Also there seem to be several alternative programs to download - how do I choose the most appropriate for Windows 10?

just do a standard Windows “copy and paste” of the text into terminal (PuTTy) if you’re not sure of the characters and then simply hit ‘enter’ on your keyboard.

and yes, it’s a lower case letter L and a lower case letter S. ie …ls is an abbreviation of the word … list

http://linuxcommand.org/lc3_man_pages/ls1.html