After updating my DokuWiki on a stick installation from Greebo to Hogfather with the latest (updated) update tool, I get the following message instead of the admin page:
Warning: require_once(D:\DokuWikiStick\dokuwiki/inc/HTTPClient.php): failed to open stream: No such file or directory in D:\DokuWikiStick\dokuwiki\lib\plugins\indexmenu\admin.php on line 11
Fatal error: require_once(): Failed opening required 'D:\DokuWikiStick\dokuwiki/inc/HTTPClient.php' (include_path='.;C:\php\pear') in D:\DokuWikiStick\dokuwiki\lib\plugins\indexmenu\admin.php on line 11
Rest of the Wiki seems to work.
I'm running it on Win 10.