Internal error

[YTMw_6KIcxg51XRH0HNUKwAAABo] /wiki/index.php?title=Sitesupport-url Error from line 178 of /usr/home/wheelsof/public_html/wiki/extensions/HeaderTabs/HeaderTabs_body.php: Call to undefined method Parser::formatHeadings()

Backtrace:

#0 /usr/home/wheelsof/public_html/wiki/extensions/HeaderTabs/HeaderTabs.hooks.php(46): HeaderTabs::replaceFirstLevelHeaders(Parser, string, array)
#1 /usr/home/wheelsof/public_html/wiki/includes/HookContainer/HookContainer.php(320): HeaderTabsHooks::replaceFirstLevelHeaders(Parser, string)
#2 /usr/home/wheelsof/public_html/wiki/includes/HookContainer/HookContainer.php(131): MediaWiki\HookContainer\HookContainer->callLegacyHook(string, array, array, array)
#3 /usr/home/wheelsof/public_html/wiki/includes/HookContainer/HookRunner.php(2894): MediaWiki\HookContainer\HookContainer->run(string, array)
#4 /usr/home/wheelsof/public_html/wiki/includes/parser/Parser.php(1693): MediaWiki\HookContainer\HookRunner->onParserAfterTidy(Parser, string)
#5 /usr/home/wheelsof/public_html/wiki/includes/parser/Parser.php(654): Parser->internalParseHalfParsed(string, boolean, boolean)
#6 /usr/home/wheelsof/public_html/wiki/includes/content/WikitextContent.php(374): Parser->parse(string, Title, ParserOptions, boolean, boolean, integer)
#7 /usr/home/wheelsof/public_html/wiki/includes/content/AbstractContent.php(590): WikitextContent->fillParserOutput(Title, integer, ParserOptions, boolean, ParserOutput)
#8 /usr/home/wheelsof/public_html/wiki/includes/Revision/RenderedRevision.php(263): AbstractContent->getParserOutput(Title, integer, ParserOptions, boolean)
#9 /usr/home/wheelsof/public_html/wiki/includes/Revision/RenderedRevision.php(235): MediaWiki\Revision\RenderedRevision->getSlotParserOutputUncached(WikitextContent, boolean)
#10 /usr/home/wheelsof/public_html/wiki/includes/Revision/RevisionRenderer.php(215): MediaWiki\Revision\RenderedRevision->getSlotParserOutput(string)
#11 /usr/home/wheelsof/public_html/wiki/includes/Revision/RevisionRenderer.php(152): MediaWiki\Revision\RevisionRenderer->combineSlotOutput(MediaWiki\Revision\RenderedRevision, array)
#12 [internal function]: MediaWiki\Revision\RevisionRenderer->MediaWiki\Revision\{closure}(MediaWiki\Revision\RenderedRevision, array)
#13 /usr/home/wheelsof/public_html/wiki/includes/Revision/RenderedRevision.php(197): call_user_func(Closure, MediaWiki\Revision\RenderedRevision, array)
#14 /usr/home/wheelsof/public_html/wiki/includes/poolcounter/PoolWorkArticleView.php(216): MediaWiki\Revision\RenderedRevision->getRevisionParserOutput()
#15 /usr/home/wheelsof/public_html/wiki/includes/poolcounter/PoolCounterWork.php(162): PoolWorkArticleView->doWork()
#16 /usr/home/wheelsof/public_html/wiki/includes/page/Article.php(810): PoolCounterWork->execute()
#17 /usr/home/wheelsof/public_html/wiki/includes/actions/ViewAction.php(74): Article->view()
#18 /usr/home/wheelsof/public_html/wiki/includes/MediaWiki.php(527): ViewAction->show()
#19 /usr/home/wheelsof/public_html/wiki/includes/MediaWiki.php(313): MediaWiki->performAction(Article, Title)
#20 /usr/home/wheelsof/public_html/wiki/includes/MediaWiki.php(940): MediaWiki->performRequest()
#21 /usr/home/wheelsof/public_html/wiki/includes/MediaWiki.php(543): MediaWiki->main()
#22 /usr/home/wheelsof/public_html/wiki/index.php(53): MediaWiki->run()
#23 /usr/home/wheelsof/public_html/wiki/index.php(46): wfIndexMain()
#24 {main}