Fatal error: OOUI\Exception: OOUI\Theme::singleton was called with no singleton theme set. in /www/wwwroot/mediawiki/vendor/oojs/oojs-ui/php/Theme.php:31 Stack trace: #0 /www/wwwroot/mediawiki/vendor/oojs/oojs-ui/php/Element.php(259): OOUI\Theme::singleton() #1 /www/wwwroot/mediawiki/vendor/oojs/oojs-ui/php/Tag.php(510): OOUI\Element->toString() #2 /www/wwwroot/mediawiki/extensions/VisualEditor/includes/Hooks.php(252): OOUI\Tag->__toString() #3 /www/wwwroot/mediawiki/includes/HookContainer/HookContainer.php(159): MediaWiki\Extension\VisualEditor\Hooks->onTextSlotDiffRendererTablePrefix() #4 /www/wwwroot/mediawiki/includes/HookContainer/HookRunner.php(1336): MediaWiki\HookContainer\HookContainer->run() #5 /www/wwwroot/mediawiki/includes/diff/TextSlotDiffRenderer.php(278): MediaWiki\HookContainer\HookRunner->onTextSlotDiffRendererTablePrefix() #6 /www/wwwroot/mediawiki/includes/diff/DifferenceEngine.php(1048): TextSlotDiffRenderer->getTablePrefix() #7 /www/wwwroot/mediawiki/includes/diff/DifferenceEngine.php(1028): DifferenceEngine->showTablePrefixes() #8 /www/wwwroot/mediawiki/includes/page/Article.php(1004): DifferenceEngine->showDiffPage() #9 /www/wwwroot/mediawiki/includes/page/Article.php(503): Article->showDiffPage() #10 /www/wwwroot/mediawiki/includes/actions/ViewAction.php(78): Article->view() #11 /www/wwwroot/mediawiki/includes/actions/ActionEntryPoint.php(733): ViewAction->show() #12 /www/wwwroot/mediawiki/includes/actions/ActionEntryPoint.php(510): MediaWiki\Actions\ActionEntryPoint->performAction() #13 /www/wwwroot/mediawiki/includes/actions/ActionEntryPoint.php(145): MediaWiki\Actions\ActionEntryPoint->performRequest() #14 /www/wwwroot/mediawiki/includes/MediaWikiEntryPoint.php(199): MediaWiki\Actions\ActionEntryPoint->execute() #15 /www/wwwroot/mediawiki/index.php(58): MediaWiki\MediaWikiEntryPoint->run() #16 {main} in /www/wwwroot/mediawiki/vendor/oojs/oojs-ui/php/Tag.php on line 512