Yea I saw that bug, it was not there earlier. I found a simple workaround. On the page change the value of active nave by adding ./ before the name. Example
$_active_nav = 'docs_general';
change it to
$_active_nav = './docs_general';
you can even add anything before / and it would work like:
$_active_nav = 'any-words/docs_general';