Thread:Project:Support desk/wfSpecialWhatlinkshere missing in \includes\SpecialWhatLinksHere/reply

The instructions you followed are horribly outdated, which is why they didn't work.

As a general rule, we recommend against patching mediawiki, because it makes upgrades difficult, and often causes unforeseen problems down the road.

(For reference, that special page is now made includable/not-includable based on which class it extends in includes/specials/SpecialWhatlinkshere.php)