SSH keys can only be added to Droplets on Droplet creation. You can add it to admin panel, but it’s only to use it on Droplet creation, restart will not add it automatically.

Make sure you type password correctly. Don’t paste it to terminal, type it yourself (you can paste it too but make sure you use right click if using Putty, or CTRL+SHIFT+V if using Linux/Mac terminal).
If you successfully changed password via Web Console, use that new password for login.

You can verify from Web Console is Password authentication and Permit root login enabled (for root password login).

Go to Console, login and open SSH config:

nano /etc/ssh/sshd_config

First locate PasswordAuthentication. Make sure it is not commented (it doesn’t have # in front of line) and is set to yes:

/etc/ssh/sshd_config
PasswordAuthentication yes

Now locate PermitRootLogin and make sure it is not commented and is set to yes:

/etc/ssh/sshd_config
PermitRootLogin yes

Now we need to restart SSH so it reflects changes:

sudo service ssh restart

Exit console and try to log in from your computer using SSH.
From there, you can add new key. You can also use ssh-copy-id if you are using Linux. It’ll add keys for you.
How To Configure SSH Key-Based Authentication on a Linux Server could help you with this.

Is this not a HUGE security hole? I’ve been using DO for years now and just now realized that deleting keys from the UI interface does not remove the keys from authorizedkeys. It appears brutally obvious right now, but I was under the impression that by removing the key from the UI I was removing the user’s access. So, I’ve had old users in my authorizedkeys file. Yikes!!

When I do:

sudo service ssh restart

I get:

Redirecting to /bin/systemctl restart ssh.service
Failed to restart ssh.service: Unit not found.

Any ideas?

This worked for me too, thanks! One thing I would add is that if you are on Windows 10, you can go to the MS store, install the Ubuntu shell, and run the “ssh-copy-id” command there. That is what I did.