Parse error: syntax error, unexpected '\' (T_NS_SEPARATOR) in /srv/initialnews/scribble/index.php(288) : regexp code on line 2

Fatal error: preg_replace(): Failed evaluating code: "<img class=\"${s}-card-poster\" src=\"" . absolute("${c.square_img_url||", $url) . "\"" in /srv/initialnews/scribble/index.php on line 288