Make this modification
https://github.com/rajeshtaneja/moodle/compare/master...wip-mdl-43521
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blocks/admin_bookmarks/block_admin_bookmarks.php
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$this->content->footer = '';
$this->page->settingsnav->initialise();
/* $node = $this->page->settingsnav->get('root', navigation_node::TYPE_SETTING); */
$node = $this->page->settingsnav->get('root', navigation_node::TYPE_SITE_ADMIN);
if (!$node || !$node->contains_active_node()) {
return $this->content;
}
===================
Now is ok!