Hello all
I also couldn't ssh to my new server unraid version 6.10.3, I followed the instructions on this thread with no success, even though none of my files shown 0 bites I also deleted all the files in /boot/config/ssh with no success.
Then I noticed that the file ident.cfg located in /boot/config had its parameter "USE_SSH" set to "no", I changed it to USE_SSH="yes" and it resolved the issue, now I can ssh into my server.
Hope this helps someone.