2020/07/10 15:36:59 [error] 30645#30645: *122671459 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught TypeError: Return value of GlobalPreferences\Hooks::getPreferencesFactory() must be an instance of GlobalPreferences\GlobalPreferencesFactory, instance of MediaWiki\Preferences\DefaultPreferencesFactory returned in /<path>/w/extensions/GlobalPreferences/includes/Hooks.php:293 Stack trace: #0 <path>/w/extensions/GlobalPreferences/includes/Hooks.php(43): GlobalPreferences\Hooks::getPreferencesFactory(Object(User)) #1 /<path>/w/includes/Hooks.php(174): GlobalPreferences\Hooks::onUserLoadOptions(Object(User), Array) #2 /<path>/w/includes/Hooks.php(202): Hooks::callHook('UserLoadOptions', Array, Array, NULL) #3 /<path>/w/includes/user/User.php(5200): Hooks::run('UserLoadOptions', Array) #4 /<path>/w/includes/user/User.php(2994): User->loadOptions() #5 /<path>/w/includes/resourceloader/ResourceLoaderUserOptionsModule.php(76): User->getOptions(1) #6 /<path>/w/includes/resourceloader/ResourceLoaderClientHtml.php(149):"
REL1_34 MediaWiki Core + GlobalPreferences.
Not sure where to start with debugging this issue found on every page load (as far as I can tell). Upgraded from REL1_32->REL1_34 and ran into this.