As it currently is written, the "Active users" information is only updated when updateSpecialPages is run. For wikis that don't have miser mode, etc. enabled, they typically don't run updateSpecialPages as their special pages are live.

Without running this at least once, you return -1 as the number of active users. Continually not running it would leave the count horribly inaccurate.

Version: 1.14.x
Severity: enhancement