#205: Fixed Class theme_trema\output\filter_manager not found.

classes/output/core_renderer.php

@@ -228,7 +228,7 @@ public function standard_head_html() {
         // If filtering of the primary custom menu is enabled, apply only the string filters.
         if (!empty(get_config('theme_trema', 'navfilter')) && strpos($CFG->additionalhtmlhead, '}') !== false) {
             // Apply filters that are enabled for Content and Headings.
-            $filtermanager = filter_manager::instance();
+            $filtermanager = \filter_manager::instance();
             $CFG->additionalhtmlhead = $filtermanager->filter_string($CFG->additionalhtmlhead, \context_system::instance());
         }