Error: Permissions 0644 for ‘/Users/xxx/.ssh/xxx.pem’ are too open. It is required that your private key files are NOT accessible by others. This private key will be ignored. Load key “/Users/xxx/.ssh/xxx.pem”: bad permissions

The above error occured when I tried to launch the new AWS instance via SSH.

How To Fix

chmod 400 ~/.ssh/xxx.pem

Works fine for me.