[f97a99c829d116539ba7c887] /index.php/Widget:Twitter_Follow_Button Error: Class "Title" not found

Backtrace:

from /usr/share/mediawiki/extensions/Widgets/WidgetRenderer.php(172)
#0 /usr/share/mediawiki/extensions/Widgets/vendor/smarty/smarty/libs/sysplugins/smarty_internal_resource_registered.php(63): WidgetRenderer::wiki_get_timestamp(string, bool, Smarty)
#1 /usr/share/mediawiki/extensions/Widgets/vendor/smarty/smarty/libs/sysplugins/smarty_internal_resource_registered.php(33): Smarty_Internal_Resource_Registered->getTemplateTimestamp(Smarty_Template_Source)
#2 /usr/share/mediawiki/extensions/Widgets/vendor/smarty/smarty/libs/sysplugins/smarty_template_source.php(182): Smarty_Internal_Resource_Registered->populate(Smarty_Template_Source, Smarty_Internal_Template)
#3 /usr/share/mediawiki/extensions/Widgets/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(168): Smarty_Template_Source::load(Smarty_Internal_Template)
#4 /usr/share/mediawiki/extensions/Widgets/vendor/smarty/smarty/libs/Smarty.class.php(1028): Smarty_Internal_Template->__construct(string, Smarty, null, null, null, null, null)
#5 /usr/share/mediawiki/extensions/Widgets/vendor/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php(189): Smarty->createTemplate(string, null, null, Smarty, bool)
#6 /usr/share/mediawiki/extensions/Widgets/vendor/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php(116): Smarty_Internal_TemplateBase->_execute(string, null, null, null, int)
#7 /usr/share/mediawiki/extensions/Widgets/WidgetRenderer.php(112): Smarty_Internal_TemplateBase->fetch(string)
#8 /usr/share/mediawiki/includes/parser/Parser.php(3492): WidgetRenderer::renderWidget(MediaWiki\Parser\Parser, string, string)
#9 /usr/share/mediawiki/includes/parser/Parser.php(3147): MediaWiki\Parser\Parser->callParserFunction(MediaWiki\Parser\PPFrame_Hash, string, array, bool)
#10 /usr/share/mediawiki/includes/parser/PPFrame_Hash.php(280): MediaWiki\Parser\Parser->braceSubstitution(array, MediaWiki\Parser\PPFrame_Hash)
#11 /usr/share/mediawiki/includes/parser/Parser.php(2970): MediaWiki\Parser\PPFrame_Hash->expand(MediaWiki\Parser\PPNode_Hash_Tree, int)
#12 /usr/share/mediawiki/includes/parser/Parser.php(1606): MediaWiki\Parser\Parser->replaceVariables(string)
#13 /usr/share/mediawiki/includes/parser/Parser.php(705): MediaWiki\Parser\Parser->internalParse(string)
#14 /usr/share/mediawiki/includes/content/WikitextContentHandler.php(380): MediaWiki\Parser\Parser->parse(string, MediaWiki\Title\Title, MediaWiki\Parser\ParserOptions, bool, bool, int)
#15 /usr/share/mediawiki/includes/content/ContentHandler.php(1743): MediaWiki\Content\WikitextContentHandler->fillParserOutput(MediaWiki\Content\WikitextContent, MediaWiki\Content\Renderer\ContentParseParams, MediaWiki\Parser\ParserOutput)
#16 /usr/share/mediawiki/includes/content/Renderer/ContentRenderer.php(75): MediaWiki\Content\ContentHandler->getParserOutput(MediaWiki\Content\WikitextContent, MediaWiki\Content\Renderer\ContentParseParams)
#17 /usr/share/mediawiki/includes/Revision/RenderedRevision.php(260): MediaWiki\Content\Renderer\ContentRenderer->getParserOutput(MediaWiki\Content\WikitextContent, MediaWiki\Page\PageIdentityValue, MediaWiki\Revision\RevisionStoreRecord, MediaWiki\Parser\ParserOptions, array)
#18 /usr/share/mediawiki/includes/Revision/RenderedRevision.php(233): MediaWiki\Revision\RenderedRevision->getSlotParserOutputUncached(MediaWiki\Content\WikitextContent, array)
#19 /usr/share/mediawiki/includes/Revision/RevisionRenderer.php(236): MediaWiki\Revision\RenderedRevision->getSlotParserOutput(string, array)
#20 /usr/share/mediawiki/includes/Revision/RevisionRenderer.php(169): MediaWiki\Revision\RevisionRenderer->combineSlotOutput(MediaWiki\Revision\RenderedRevision, MediaWiki\Parser\ParserOptions, array)
#21 /usr/share/mediawiki/includes/Revision/RenderedRevision.php(196): MediaWiki\Revision\RevisionRenderer->{closure:MediaWiki\Revision\RevisionRenderer::getRenderedRevision():167}(MediaWiki\Revision\RenderedRevision, array)
#22 /usr/share/mediawiki/includes/poolcounter/PoolWorkArticleView.php(110): MediaWiki\Revision\RenderedRevision->getRevisionParserOutput()
#23 /usr/share/mediawiki/includes/poolcounter/PoolWorkArticleViewCurrent.php(129): MediaWiki\PoolCounter\PoolWorkArticleView->renderRevision(null, bool, string)
#24 /usr/share/mediawiki/includes/poolcounter/PoolCounterWork.php(173): MediaWiki\PoolCounter\PoolWorkArticleViewCurrent->doWork()
#25 /usr/share/mediawiki/includes/page/ParserOutputAccess.php(364): MediaWiki\PoolCounter\PoolCounterWork->execute()
#26 /usr/share/mediawiki/includes/page/Article.php(834): MediaWiki\Page\ParserOutputAccess->getParserOutput(MediaWiki\Page\WikiPage, MediaWiki\Parser\ParserOptions, MediaWiki\Revision\RevisionStoreRecord, int)
#27 /usr/share/mediawiki/includes/page/Article.php(551): MediaWiki\Page\Article->generateContentOutput(MediaWiki\User\User, MediaWiki\Parser\ParserOptions, int, MediaWiki\Output\OutputPage, array)
#28 /usr/share/mediawiki/includes/actions/ViewAction.php(80): MediaWiki\Page\Article->view()
#29 /usr/share/mediawiki/includes/actions/ActionEntryPoint.php(728): MediaWiki\Actions\ViewAction->show()
#30 /usr/share/mediawiki/includes/actions/ActionEntryPoint.php(505): MediaWiki\Actions\ActionEntryPoint->performAction(MediaWiki\Page\Article, MediaWiki\Title\Title)
#31 /usr/share/mediawiki/includes/actions/ActionEntryPoint.php(143): MediaWiki\Actions\ActionEntryPoint->performRequest()
#32 /usr/share/mediawiki/includes/MediaWikiEntryPoint.php(202): MediaWiki\Actions\ActionEntryPoint->execute()
#33 /usr/share/mediawiki/index.php(58): MediaWiki\MediaWikiEntryPoint->run()
#34 {main}