Eg access to https://tuleap.net/plugins/docman/?group_id=1
2017/10/19 06:58:05 [error] 18284#0: *267293 FastCGI sent in stderr: "PHP message: PHP Fatal error: Call to a member function displayHeader() on null in /usr/share/tuleap/plugins/docman/include/view/Docman_View_Header.class.php on line 47" while reading response header from upstream, client: X, server: tuleap.net, request: "GET /plugins/docman/?group_id=1&action=details&id=1 HTTP/1.1"