From HHVM error log:
Notice: Cannot access property on non-object in /var/www/live/w/includes/SiteStats.php on line 57 Notice: Cannot access property on non-object in /var/www/live/w/includes/SiteStats.php on line 142
The code bug causing this was fixed in {rSHWK3844} but the maintenance script needs to be run globally unless we have a way of identifying which wikis are causing these E_NOTICEs, which I don't think we do. I guess that while we're at it, we can also update the amount of active users (the --active option). Note that for whatever mind-boggling reason, /maintenance/initSiteStats.php has to be called with the --update option to actually perform the updates. (What's the logic behind this? Beats me...)