He means to comment the codeCan you be more specific, what do you mean "comment with double backslash", can you just post the code change so I can copy/paste? Thanks!
from
add_action( 'admin_notices', array( $this, 'activation_license_notice' ), 15 );
to
//add_action( 'admin_notices', array( $this, 'activation_license_notice' ), 15 );