=== Error ===
Request ID: `W9SiTwpAIC0AAFDHQdQAAABT `
```name=message
BadMethodCallException: Call to a member function getRepresentationsz
```
```name=trace,lines=10
#0 /srv/mediawiki/php-1.33.0-wmf.1/extensions/WikibaseLexeme/src/MediaWiki/EntityLinkFormatters/FormLinkFormatter.php(63): Wikibase\Lexeme\MediaWiki\EntityLinkFormatters\FormLinkFormatter->getRepresentations(Wikibase\Lexeme\Domain\Model\FormId)
#1 /srv/mediawiki/php-1.33.0-wmf.1/extensions/Wikibase/repo/includes/Hooks/HtmlPageLinkRendererBeginHookHandler.php(253): Wikibase\Lexeme\MediaWiki\EntityLinkFormatters\FormLinkFormatter->getHtml(Wikibase\Lexeme\Domain\Model\FormId, NULL)
#2 /srv/mediawiki/php-1.33.0-wmf.1/extensions/Wikibase/repo/includes/Hooks/HtmlPageLinkRendererBeginHookHandler.php(141): Wikibase\Repo\Hooks\HtmlPageLinkRendererBeginHookHandler->doHtmlPageLinkRendererBegin(MediaWiki\Linker\LinkRenderer, Title, HtmlArmor, array, RequestContext, NULL)
#3 /srv/mediawiki/php-1.33.0-wmf.1/includes/Hooks.php(174): Wikibase\Repo\Hooks\HtmlPageLinkRendererBeginHookHandler::onHtmlPageLinkRendererBegin(MediaWiki\Linker\LinkRenderer, Title, HtmlArmor, array, array, NULL)
#4 /srv/mediawiki/php-1.33.0-wmf.1/includes/Hooks.php(202): Hooks::callHook(string, array, array, NULL)
#5 /srv/mediawiki/php-1.33.0-wmf.1/includes/linker/LinkRenderer.php(180): Hooks::run(string, array)
#6 /srv/mediawiki/php-1.33.0-wmf.1/includes/linker/LinkRenderer.php(251): MediaWiki\Linker\LinkRenderer->runBeginHook(Title, HtmlArmor, array, array, boolean)
#7 /srv/mediawiki/php-1.33.0-wmf.1/includes/parser/LinkHolderArray.php(401): MediaWiki\Linker\LinkRenderer->makePreloadedLink(Title, HtmlArmor, string, array, array)
#8 /srv/mediawiki/php-1.33.0-wmf.1/includes/parser/LinkHolderArray.php(272): LinkHolderArray->replaceInternal(string)
#9 /srv/mediawiki/php-1.33.0-wmf.1/includes/parser/Parser.php(4991): LinkHolderArray->replace(string)
#10 /srv/mediawiki/php-1.33.0-wmf.1/includes/parser/Parser.php(1417): Parser->replaceLinkHolders(string)
#11 /srv/mediawiki/php-1.33.0-wmf.1/includes/parser/Parser.php(485): Parser->internalParseHalfParsed(string, boolean, boolean)
#12 /srv/mediawiki/php-1.33.0-wmf.1/includes/content/WikitextContent.php(341): Parser->parse(string, Title, ParserOptions, boolean, boolean, integer)
#13 /srv/mediawiki/php-1.33.0-wmf.1/includes/content/AbstractContent.php(517): WikitextContent->fillParserOutput(Title, integer, ParserOptions, boolean, ParserOutput)
#14 /srv/mediawiki/php-1.33.0-wmf.1/includes/Revision/RenderedRevision.php(243): AbstractContent->getParserOutput(Title, integer, ParserOptions, boolean)
#15 /srv/mediawiki/php-1.33.0-wmf.1/includes/Revision/RenderedRevision.php(211): MediaWiki\Revision\RenderedRevision->getSlotParserOutputUncached(WikitextContent, boolean)
#16 /srv/mediawiki/php-1.33.0-wmf.1/includes/Revision/RevisionRenderer.php(168): MediaWiki\Revision\RenderedRevision->getSlotParserOutput(string)
#17 /srv/mediawiki/php-1.33.0-wmf.1/includes/Revision/RevisionRenderer.php(121): MediaWiki\Revision\RevisionRenderer->combineSlotOutput(MediaWiki\Revision\RenderedRevision, array)
#18 [internal function]: Closure$MediaWiki\Revision\RevisionRenderer::getRenderedRevision#2(MediaWiki\Revision\RenderedRevision, array)
#19 /srv/mediawiki/php-1.33.0-wmf.1/includes/Revision/RenderedRevision.php(175): call_user_func(Closure$MediaWiki\Revision\RevisionRenderer::getRenderedRevision#2;2739, MediaWiki\Revision\RenderedRevision, array)
#20 /srv/mediawiki/php-1.33.0-wmf.1/includes/poolcounter/PoolWorkArticleView.php(194): MediaWiki\Revision\RenderedRevision->getRevisionParserOutput()
#21 /srv/mediawiki/php-1.33.0-wmf.1/includes/poolcounter/PoolCounterWork.php(123): PoolWorkArticleView->doWork()
#22 /srv/mediawiki/php-1.33.0-wmf.1/includes/page/WikiPage.php(1230): PoolCounterWork->execute()
#23 /srv/mediawiki/php-1.33.0-wmf.1/includes/diff/DifferenceEngine.php(920): WikiPage->getParserOutput(ParserOptions, integer)
#24 /srv/mediawiki/php-1.33.0-wmf.1/includes/diff/DifferenceEngine.php(881): DifferenceEngine->getParserOutput(WikiPage, Revision)
#25 /srv/mediawiki/php-1.33.0-wmf.1/includes/diff/DifferenceEngine.php(709): DifferenceEngine->renderNewRevision()
#26 /srv/mediawiki/php-1.33.0-wmf.1/includes/page/Article.php(932): DifferenceEngine->showDiffPage(boolean)
#27 /srv/mediawiki/php-1.33.0-wmf.1/includes/page/Article.php(616): Article->showDiffPage()
#28 /srv/mediawiki/php-1.33.0-wmf.1/includes/actions/ViewAction.php(68): Article->view()
#29 /srv/mediawiki/php-1.33.0-wmf.1/includes/MediaWiki.php(501): ViewAction->show()
#30 /srv/mediawiki/php-1.33.0-wmf.1/includes/MediaWiki.php(294): MediaWiki->performAction(Article, Title)
#31 /srv/mediawiki/php-1.33.0-wmf.1/includes/MediaWiki.php(860): MediaWiki->performRequest()
#32 /srv/mediawiki/php-1.33.0-wmf.1/includes/MediaWiki.php(517): MediaWiki->main()
```
=== Impact ===
Some Wikidata.org urls cannot be viewed by users. They receive a fatal PHP error, and produce HTTP 5xx responses that cannot be cached.
Example at `https://www.wikidata.org/w/index.php?title=Wikidata_talk%3ALexicographical_data&type=revision&diff=749258955&oldid=749093415`.
=== Notes ===
This started yesterday with the deployment of 1.33-wmf.1.