Get some warnings

Hello!

First of all: Thank you for that nice tool, @archetyped !

But… I’ve got an issue, actually two:
I use the plugin »Code Snippets« by »Code Snippets Pro« and »Blog2Social« by »Blog2Social, Adenion«.

When I want to edit an snippet or going to chose a post for sharing, these messages occur (the plugins work well, as far as I can see):

Warning: count(): Parameter must be an array or an object that implements Countable in [...]/wp-content/plugins/cornerstone/includes/class.utilities.php on line 857

Warning: Cannot modify header information - headers already sent by (output started at [...]/wp-content/plugins/cornerstone/includes/class.utilities.php:857) in [...]/wp-includes/functions.php on line 6221

Warning: Cannot modify header information - headers already sent by (output started at [...]/wp-content/plugins/cornerstone/includes/class.utilities.php:857) in [...]/wp-admin/includes/misc.php on line 1259

Warning: Cannot modify header information - headers already sent by (output started at [...]/wp-content/plugins/cornerstone/includes/class.utilities.php:857) in [...]/wp-admin/admin-header.php on line 9

Warning: count(): Parameter must be an array or an object that implements Countable in [...]/wp-content/plugins/cornerstone/includes/class.utilities.php on line 857

Warning: count(): Parameter must be an array or an object that implements Countable in [...]/wp-content/plugins/cornerstone/includes/class.utilities.php on line 857

Warning: count(): Parameter must be an array or an object that implements Countable in [...]/wp-content/plugins/cornerstone/includes/class.utilities.php on line 857

Thanks a lot for fixing this!