Cannot use object of type stdClass as array

from /srv/mediawiki/w/extensions/AJAXPoll/includes/AJAXPoll.php(405)
#0 /srv/mediawiki/w/extensions/AJAXPoll/includes/AJAXPoll.php(129): AJAXPoll::buildHTML(string, User, boolean, array)
#1 /srv/mediawiki/w/includes/parser/Parser.php(3973): AJAXPoll::render(string, array, Parser, PPFrame_Hash)
#2 /srv/mediawiki/w/includes/parser/PPFrame_Hash.php(350): Parser->extensionSubstitution(array, PPFrame_Hash)
#3 /srv/mediawiki/w/includes/parser/Parser.php(2930): PPFrame_Hash->expand(PPNode_Hash_Tree, integer)
#4 /srv/mediawiki/w/includes/parser/Parser.php(1598): Parser->replaceVariables(string)
#5 /srv/mediawiki/w/includes/parser/Parser.php(656): Parser->internalParse(string)
#6 /srv/mediawiki/w/includes/content/WikitextContent.php(327): Parser->parse(string, Title, ParserOptions, boolean, boolean, integer)
#7 /srv/mediawiki/w/includes/content/AbstractContent.php(548): WikitextContent->fillParserOutput(Title, integer, ParserOptions, boolean, ParserOutput)
#8 /srv/mediawiki/w/includes/Revision/RenderedRevision.php(263): AbstractContent->getParserOutput(Title, integer, ParserOptions, boolean)
#9 /srv/mediawiki/w/includes/Revision/RenderedRevision.php(235): MediaWiki\Revision\RenderedRevision->getSlotParserOutputUncached(WikitextContent, boolean)
#10 /srv/mediawiki/w/includes/Revision/RevisionRenderer.php(217): MediaWiki\Revision\RenderedRevision->getSlotParserOutput(string, array)
#11 /srv/mediawiki/w/includes/Revision/RevisionRenderer.php(154): MediaWiki\Revision\RevisionRenderer->combineSlotOutput(MediaWiki\Revision\RenderedRevision, array)
#12 [internal function]: MediaWiki\Revision\RevisionRenderer->MediaWiki\Revision\{closure}(MediaWiki\Revision\RenderedRevision, array)
#13 /srv/mediawiki/w/includes/Revision/RenderedRevision.php(197): call_user_func(Closure, MediaWiki\Revision\RenderedRevision, array)
#14 /srv/mediawiki/w/includes/poolcounter/PoolWorkArticleView.php(137): MediaWiki\Revision\RenderedRevision->getRevisionParserOutput()
#15 /srv/mediawiki/w/includes/poolcounter/PoolCounterWork.php(162): PoolWorkArticleView->doWork()
#16 /srv/mediawiki/w/includes/page/ParserOutputAccess.php(281): PoolCounterWork->execute()
#17 /srv/mediawiki/w/includes/page/Article.php(691): MediaWiki\Page\ParserOutputAccess->getParserOutput(WikiPage, ParserOptions, MediaWiki\Revision\RevisionStoreCacheRecord, integer)
#18 /srv/mediawiki/w/includes/page/Article.php(506): Article->generateContentOutput(User, ParserOptions, integer, OutputPage, array)
#19 /srv/mediawiki/w/includes/actions/ViewAction.php(80): Article->view()
#20 /srv/mediawiki/w/includes/MediaWiki.php(543): ViewAction->show()
#21 /srv/mediawiki/w/includes/MediaWiki.php(320): MediaWiki->performAction(Article, Title)
#22 /srv/mediawiki/w/includes/MediaWiki.php(930): MediaWiki->performRequest()
#23 /srv/mediawiki/w/includes/MediaWiki.php(564): MediaWiki->main()
#24 /srv/mediawiki/w/index.php(53): MediaWiki->run()
#25 /srv/mediawiki/w/index.php(46): wfIndexMain()
#26 {main}