IE 11's developer tools (F12) warned when visiting /configureSecurity/ that <link rel='stylesheet' href='/jenkins/adjuncts/.../lib/form/section_.css' type='text/css' /> was an "unexpected token", probably meaning that this occurred in the body of the document (inside the table in <td class="setting-main">) when it is supposed to be only in the head. Seems like a Stapler bug: adjuncts (here <st:adjunct includes="lib.form.section_" /> from lib/form/section.jelly) are supposed to be emitted in the head.