Fatal error: OOUI\Exception: OOUI\Theme::singleton was called with no singleton theme set. in /home/qelnet/public_html/fa/vendor/oojs/oojs-ui/php/Theme.php:31 Stack trace: #0 /home/qelnet/public_html/fa/vendor/oojs/oojs-ui/php/Element.php(259): OOUI\Theme::singleton() #1 /home/qelnet/public_html/fa/vendor/oojs/oojs-ui/php/Tag.php(507): OOUI\Element->toString() #2 /home/qelnet/public_html/fa/extensions/VisualEditor/includes/Hooks.php(244): OOUI\Tag->__toString() #3 /home/qelnet/public_html/fa/includes/HookContainer/HookContainer.php(161): MediaWiki\Extension\VisualEditor\Hooks->onTextSlotDiffRendererTablePrefix(Object(TextSlotDiffRenderer), Object(RequestContext), Array) #4 /home/qelnet/public_html/fa/includes/HookContainer/HookRunner.php(1334): MediaWiki\HookContainer\HookContainer->run('TextSlotDiffRen...', Array) #5 /home/qelnet/public_html/fa/includes/diff/TextSlotDiffRenderer.php(273): MediaWiki\HookContainer\HookRunner->onTextSlotDiffRendererTablePrefix(Object(TextSlotDiffRenderer), Object(RequestContext), Array) #6 in /home/qelnet/public_html/fa/vendor/oojs/oojs-ui/php/Tag.php on line 509