I created an SSH public key for my root user. I copied it to /root/.ssh/authorized_keys, and saved.
The key is only
ssh-rsa key. (It's one row,
ssh-rsaSPACEkey, no further spaces or brakes).
owner and group are same as the USERNAME.
I can log in SSH just fine with root and I repeated the same algorithm for creating, pasting and loading the key, for my primary user under
/home/USERNAME but I can't login with it - It says "No supported authentication methods available".
I did load private keys for both of these users.
Both keys are ssh-2 rsa.
Both keys include 4096 bytes.
I use Putty to login, and load the private keys with pageant.
service ssh restartbefore trying.
Update 1 - Relevant public key:
Here's he public key I'm having problems with (copied as is from /home/USERNAME/.ssh/authrorized_keys):
Update 2 - Seemingly-relevant sshd_config directives
I put an image as for some reason I can't paste syntax I cut or copy from Putty: