Upon deploying to non-WP projects:
PHP Error: Argument 1 passed to CentralIdLookup::namesFromCentralIds() must be an instance of array, string given #0 /srv/mediawiki/php-1.31.0-wmf.26/includes/user/CentralIdLookup.php(180): MWExceptionHandler::handleError(integer, string, string, integer, array, array) #1 /srv/mediawiki/php-1.31.0-wmf.26/extensions/Echo/Hooks.php(494): CentralIdLookup->namesFromCentralIds(string, User) #2 /srv/mediawiki/php-1.31.0-wmf.26/includes/Hooks.php(177): EchoHooks::getPreferences(User, array) #3 /srv/mediawiki/php-1.31.0-wmf.26/includes/Hooks.php(205): Hooks::callHook(string, array, array, NULL) #4 /srv/mediawiki/php-1.31.0-wmf.26/includes/preferences/DefaultPreferencesFactory.php(137): Hooks::run(string, array) #5 /srv/mediawiki/php-1.31.0-wmf.26/extensions/GlobalPreferences/includes/GlobalPreferencesFactory.php(106): MediaWiki\Preferences\DefaultPreferencesFactory->getFormDescriptor(User, RequestContext) #6 /srv/mediawiki/php-1.31.0-wmf.26/extensions/GlobalPreferences/includes/GlobalPreferencesFactory.php(343): GlobalPreferences\GlobalPreferencesFactory->getFormDescriptor(User, RequestContext) #7 /srv/mediawiki/php-1.31.0-wmf.26/extensions/GlobalPreferences/includes/Hooks.php(162): GlobalPreferences\GlobalPreferencesFactory->setGlobalPreferences(array, RequestContext) #8 /srv/mediawiki/php-1.31.0-wmf.26/includes/Hooks.php(177): GlobalPreferences\Hooks::onPreferencesFormPreSave(array, GlobalPreferences\GlobalPreferencesForm, User, boolean, array) #9 /srv/mediawiki/php-1.31.0-wmf.26/includes/Hooks.php(205): Hooks::callHook(string, array, array, NULL) #10 /srv/mediawiki/php-1.31.0-wmf.26/includes/preferences/DefaultPreferencesFactory.php(1602): Hooks::run(string, array) #11 /srv/mediawiki/php-1.31.0-wmf.26/includes/preferences/DefaultPreferencesFactory.php(1632): MediaWiki\Preferences\DefaultPreferencesFactory->saveFormData(array, GlobalPreferences\GlobalPreferencesForm) #12 /srv/mediawiki/php-1.31.0-wmf.26/includes/preferences/DefaultPreferencesFactory.php(1433): MediaWiki\Preferences\DefaultPreferencesFactory->submitForm(array, GlobalPreferences\GlobalPreferencesForm) #13 /srv/mediawiki/php-1.31.0-wmf.26/includes/htmlform/HTMLForm.php(671): Closure$MediaWiki\Preferences\DefaultPreferencesFactory::getForm(array, GlobalPreferences\GlobalPreferencesForm) #14 /srv/mediawiki/php-1.31.0-wmf.26/includes/htmlform/HTMLForm.php(563): HTMLForm->trySubmit() #15 /srv/mediawiki/php-1.31.0-wmf.26/includes/htmlform/HTMLForm.php(578): HTMLForm->tryAuthorizedSubmit() #16 /srv/mediawiki/php-1.31.0-wmf.26/includes/specials/SpecialPreferences.php(118): HTMLForm->show() #17 /srv/mediawiki/php-1.31.0-wmf.26/extensions/GlobalPreferences/includes/SpecialGlobalPreferences.php(63): SpecialPreferences->execute(NULL) #18 /srv/mediawiki/php-1.31.0-wmf.26/includes/specialpage/SpecialPage.php(522): GlobalPreferences\SpecialGlobalPreferences->execute(NULL) #19 /srv/mediawiki/php-1.31.0-wmf.26/includes/specialpage/SpecialPageFactory.php(579): SpecialPage->run(NULL) #20 /srv/mediawiki/php-1.31.0-wmf.26/includes/MediaWiki.php(288): SpecialPageFactory::executePath(Title, RequestContext) #21 /srv/mediawiki/php-1.31.0-wmf.26/includes/MediaWiki.php(861): MediaWiki->performRequest() #22 /srv/mediawiki/php-1.31.0-wmf.26/includes/MediaWiki.php(524): MediaWiki->main() #23 /srv/mediawiki/php-1.31.0-wmf.26/index.php(42): MediaWiki->run() #24 /srv/mediawiki/w/index.php(3): include(string) #25 {main}
Seems to have something to do with the user blacklist.