Notice: Undefined index: meta-robots-noindex in /home/lnemettr/public_html/wp-content/plugins/wordpress-seo/inc/class-wpseo-meta.php on line 423
Because it is unset on line 421. Moving the order of these removes the notice.
There is a second notice appearing as well, Notice: Undefined index: type in /home/lnemettr/public_html/wp-content/plugins/wordpress-seo/admin/class-metabox.php on line 667
but that disappears when the first error is fixed.
How to repeat:
in wp-config.php, set WP_DEBUG to true
In Settings -> Reading, check "Discourage search engines from indexing this site"
Edit an existing page
@benfreke Thank you for reporting. This should be fixed with pull request #752.
Closing as pull request is now merged in master.