Internal error

From Yade

[1feb15fc74fb5c86de76a58f] /w/index.php?title=Category:Community&oldid=103 Error from line 1608 of /usr/share/mediawiki/includes/page/Article.php: Call to a member function getTimestamp() on null

Backtrace:

#0 /usr/share/mediawiki/includes/page/Article.php(737): Article->setOldSubtitle()
#1 /usr/share/mediawiki/includes/page/CategoryPage.php(63): Article->view()
#2 /usr/share/mediawiki/includes/actions/ViewAction.php(80): CategoryPage->view()
#3 /usr/share/mediawiki/includes/MediaWiki.php(531): ViewAction->show()
#4 /usr/share/mediawiki/includes/MediaWiki.php(313): MediaWiki->performAction()
#5 /usr/share/mediawiki/includes/MediaWiki.php(947): MediaWiki->performRequest()
#6 /usr/share/mediawiki/includes/MediaWiki.php(547): MediaWiki->main()
#7 /usr/share/mediawiki/index.php(53): MediaWiki->run()
#8 /usr/share/mediawiki/index.php(46): wfIndexMain()
#9 {main}