This is probably a stupidly simple question to some :)
I\'ve created a new linux instance on Amazon EC2, and as part of that downloaded the .pem file to allow me to
The issue for me was that my .pem file was in one of my NTFS partitions. I moved it to my linux partition (ext4).
Gave required permissions by running:
chmod 400 my_file.pem
And it worked.