AWS CLI Config profile not found
Solution 1:
When you give a profile name or change the default profile name you're effectively saying 'i want to use a named profile in my crednetials file'.
so what you've done here is said 'use the profile called 'ken' as my default, but your default profile is called 'default' not 'ken'.
Typically this ability is used to have profiles called 'dev' or 'prod' etc, and i'd advise making dev the 'default' as opposed to prod to avoid unexpected mishaps.