I am using windows with Putty.
I converted the PEM file to a PPK file using PuttyGen and have been following the instructions here: https://linuxacademy.com/blog/linux/connect-to-amazon-ec2-using-putty-private-key-on-windows/ to connect to the server.
When I try to connect using root, it says to login using ubunto username.
But when I login using ubunto username, an error appears. Any advice?