Sometimes, after you makes changes to a .ssh/config file, you'll start to see the following error when you try to connect to a host:

Bad owner or permissions on /share/homes/admin/.ssh/config

This is because the permissions have been altered on the config file. Fix it with this:

chmod 700 ~/.ssh
chmod 600 ~/.ssh/*

Source: https://superuser.com/questions/1212402/bad-owner-or-permissions-on-ssh-config-file