External HDD (Apple_HFS) not recognised by Finder under Sierra 10.12.6 my external HDD (used for TM backups and some other stuff) suddenly stopped working with my MBP 2017 (Sierra 10.12.6). I can see it only through the Terminal (see screenshot 1)



DiskUtility won't load when this particular HDD is plugged. I have also tried several diskutil command lines:

verifyVolume &amp; repairVolume


verifyDisk


repairDisk


Did not perform the last one, cause I really don't want to lose my data.
Tested on two Windows machines with Apple_HFS driver. Driver was found and data are just fine and readable. 

Someone with an idea how to fix this without losing data? Any help will be appreciated!
The problem is solved. I gave it another try in Safe-Mode and voila - my external HDD was visible, so I made "First-Aid" and did a reboot into normal mode back again. Everything seems to be fine now.