Right after I saved this change
https://pt.wikipedia.org/w/index.php?title=T%C3%B3pico:Sk4rd4ls60jwgjn1&action=compare-post-revisions&topic_newRevision=sk5tq5s0swahor3k
I got the following error:
{ "errorMessage":"TypeError: helpers.helperMissing.call is not a function", "url":"https://pt.wikipedia.org/w/load.php?debug=false&lang=pt&modules=ext.cirrusSearch.loggingSchema%7Cext.cx.campaigns.contributionsmenu%7Cext.cx.eventlogging%2Cmodel%7Cext.cx.widgets.callout%7Cext.echo.base%2Coverlay%7Cext.echo.overlay.init%7Cext.eventLogging.subscriber%7Cext.flow%2CnavigationTiming%2Cthanks%2CwikimediaEvents%7Cext.flow.components%2Cdm%2Ceditor%2Ctemplating%7Cext.flow.jquery.conditionalScroll%2CfindWithParent%7Cext.flow.vendor.storer%7Cext.gadget.APC%2CBugStatusUpdate%2CFeedbackHighlight%2CHotCat%2CNewVillagePump%2CPagesForDeletion%2CReferenceTooltips%2CSVGPNG%2CSysopSuggestions%2CUploadForm%2Cfastbuttons%2Cfeatured-articles-links%2Cgeonotice%7Cext.gadget.mediawiki.api.ptwiki%7Cext.imageMetrics.loader%7Cext.thanks.flowthank%7Cext.uls.eventlogger%2Cinterlanguage%7Cext.visualEditor.targetLoader%7Cext.wikimediaEvents.loggedin%2Cstatsd%7Cjquery.checkboxShiftClick%2CgetAttrs%2ChighlightText%2CmakeCollapsible%2Cmw-jump%2Cplaceholder%2Cspinner%2Csuggestions%7Cmediawiki.api.options%2Cwatch%7Cmediawiki.page.ready%7Cmediawiki.page.watch.ajax%7Cmediawiki.searchSuggest%2Ctemplate%7Cmediawiki.template.handlebars%7Cmediawiki.ui.anchor%2Cbutton%7Cmoment%2Coojs%7Cschema.Echo%2CEchoInteraction%2CEchoMail%2CFlowReplies%2CNavigationTiming%2CSaveTiming%2CSearch%2CUniversalLanguageSelector%7Cwikibase.client.linkitem.init&skin=vector&version=5f3c78f06c5f&* line 447 > Function", "lineNumber":6, "columnNumber":31, "errorObject":{ } }
I was using Firefox 38.0 on Linux.