I found a soloution and what causes it.
It was not really the delimiter that was the problem it was becasue a user made duplicate posts.
Solution:
Replace
$notify_message .= preg_replace('#[\s]+#', ' ',sprintf( get_comment_meta($comment->comment_ID, 'title',1))) .' skrev:'. "\r\n" . $comment->comment_content . "\r\n\r\n";
With
$notify_message = preg_replace('/[\s]+/', ' ',sprintf( get_comment_meta($comment->comment_ID, 'title',1)) .' skrev:'. "\r\n" . $comment->comment_content . "\r\n\r\n");
And add following code to function.php in your theme, that will allow same user to make dubplacte post:
add_filter( 'wp_die_handler', 'my_wp_die_handler_function', 9 ); //9 means you can unhook the default before it fires
function my_wp_die_handler_function($function) {
return 'my_skip_dupes_function'; //use our "die" handler instead (where we won't die)
}
//check to make sure we're only filtering out die requests for the "Duplicate" error we care about
function my_skip_dupes_function( $message, $title, $args ) {
if (strpos( $message, 'Duplicate comment detected' ) === 0 ) { //make sure we only prevent death on the $dupe check
remove_filter( 'wp_die_handler', '_default_wp_die_handler' ); //don't die
}
return; //nothing will happen
}