Warning after install and only selecting "Enable PHP"

Obviously running in dev mode, but this warning is showing up after I only enabled PHP support.

Notice: Undefined index: shortcode in /Users/foo/Documents/Sites/wordpress/wp-content/plugins/enable-shortcode-and-php-support-in-text-widget/enable-shortcode-and-php-support-in-text-widget.php on line 138

If I enable shortcode support it goes away (albeit with another error and after refreshing the page)

Notice: Undefined index: shortcode in /Users/foo/Documents/Sites/wordpress/wp-content/plugins/enable-shortcode-and-php-support-in-text-widget/enable-shortcode-and-php-support-in-text-widget.php on line 138

Warning: Cannot modify header information - headers already sent by (output started at /Users/foo/Documents/Sites/wordpress/wp-content/plugins/enable-shortcode-and-php-support-in-text-widget/enable-shortcode-and-php-support-in-text-widget.php:138) in /Users/foo/Documents/Sites/wordpress/wp-includes/pluggable.php on line 1121

https://www.ads-software.com/plugins/enable-shortcode-and-php-support-in-text-widget/