Fatal error: OOUI\Exception: OOUI\Theme::singleton was called with no singleton theme set. in /galbaike/vendor/oojs/oojs-ui/php/Theme.php:31 Stack trace: #0 /galbaike/vendor/oojs/oojs-ui/php/Element.php(259): OOUI\Theme::singleton() #1 /galbaike/vendor/oojs/oojs-ui/php/Tag.php(507): OOUI\Element->toString() #2 /galbaike/extensions/VisualEditor/includes/Hooks.php(244): OOUI\Tag->__toString() #3 /galbaike/includes/HookContainer/HookContainer.php(161): MediaWiki\Extension\VisualEditor\Hooks->onTextSlotDiffRendererTablePrefix() #4 /galbaike/includes/HookContainer/HookRunner.php(1332): MediaWiki\HookContainer\HookContainer->run() #5 /galbaike/includes/diff/TextSlotDiffRenderer.php(273): MediaWiki\HookContainer\HookRunner->onTextSlotDiffRendererTablePrefix() #6 /galbaike/includes/diff/DifferenceEngine.php(942): TextSlotDiffRenderer->getTablePrefix() #7 /galbaike/includes/diff/DifferenceEngine.php(928): DifferenceEngine->showTablePrefixes() #8 /galbaike/includes/page/Article.php(979): DifferenceEngine->showDiffPage() #9 /galbaike/includes/page/Article.php(490): Article->showDiffPage() #10 /galbaike/includes/actions/ViewAction.php(78): Article->view() #11 /galbaike/includes/MediaWiki.php(583): ViewAction->show() #12 /galbaike/includes/MediaWiki.php(363): MediaWiki->performAction() #13 /galbaike/includes/MediaWiki.php(960): MediaWiki->performRequest() #14 /galbaike/includes/MediaWiki.php(613): MediaWiki->main() #15 /galbaike/index.php(50): MediaWiki->run() #16 /galbaike/index.php(46): wfIndexMain() #17 {main} in /galbaike/vendor/oojs/oojs-ui/php/Tag.php on line 509