Well, that was a frustrating experience.

I’ve been running AWS instances for 8+ years and am a CCSP, Cloud Computing Security Professional.

A few days ago I tried to spin up a new Ubuntu instance in a new AWS region. Did the all the steps that I usually do including generating new keys for that region. Every time I would try to SSH in to the server, I kept receiving: “Server Refused Our Key”.

I made new keys. I spun up new instances with new settings. I tried different usernames. I converted keys from .ppk to .pem. Nothing worked.

And then I found a little snipped on askubuntu.com that said to upgrade from PuTTY 0.76 to PuTTY 0.77. And now it works.