After updating to the latest version of MediaWiki (1.42.1), I can no longer click any Preference tabs (other than User profile). I can't click (and go to) any of these tabs: Appearance, Editing, Recent changes, Watchlist, Search. I CAN change and save stuff in the 'User profile' tab.
Also, 'Edit' no longer works; only 'Edit source'.
Can someone help me fix this?