I am seeing a php error:
PHP Fatal error: [] operator not supported for strings in /wp-content/plugins/gnu-terry-pratchett/gnu-terry-pratchett.php on line 56
Line 56:
$args['headers'][] = "X-Clacks-Overhead: GNU Terry Pratchett";
Accordngt to the wp_mail codex, $args['headers'] can be an array or a string with lines delimited with \r\n.
So this line needs to be changed to handle both types array or string.
And this is probably why CF7 stops working.