内部エラー

[ZgVEx3xjN_ZBKsdWIOdnQQAAAck] /wiki/index.php?title=%E5%B0%86%E6%A3%8B%E7%94%9F%E4%B8%BB%E4%B8%80%E8%A6%A7&diff=2551&oldid=2447 Error: Call to a member function getUser() on null

Backtrace:

from /home/huwaneko/shogi.fun/public_html/niconico/wiki/includes/diff/DifferenceEngine.php(1677)
#0 /home/huwaneko/shogi.fun/public_html/niconico/wiki/includes/diff/DifferenceEngine.php(1204): DifferenceEngine->getMultiNotice()
#1 /home/huwaneko/shogi.fun/public_html/niconico/wiki/includes/diff/DifferenceEngine.php(1159): DifferenceEngine->getDiff(string, string, string)
#2 /home/huwaneko/shogi.fun/public_html/niconico/wiki/includes/diff/DifferenceEngine.php(922): DifferenceEngine->showDiff(string, string, string)
#3 /home/huwaneko/shogi.fun/public_html/niconico/wiki/includes/page/Article.php(952): DifferenceEngine->showDiffPage(boolean)
#4 /home/huwaneko/shogi.fun/public_html/niconico/wiki/includes/page/Article.php(486): Article->showDiffPage()
#5 /home/huwaneko/shogi.fun/public_html/niconico/wiki/includes/actions/ViewAction.php(78): Article->view()
#6 /home/huwaneko/shogi.fun/public_html/niconico/wiki/includes/MediaWiki.php(556): ViewAction->show()
#7 /home/huwaneko/shogi.fun/public_html/niconico/wiki/includes/MediaWiki.php(333): MediaWiki->performAction(Article, MediaWiki\Title\Title)
#8 /home/huwaneko/shogi.fun/public_html/niconico/wiki/includes/MediaWiki.php(923): MediaWiki->performRequest()
#9 /home/huwaneko/shogi.fun/public_html/niconico/wiki/includes/MediaWiki.php(576): MediaWiki->main()
#10 /home/huwaneko/shogi.fun/public_html/niconico/wiki/index.php(50): MediaWiki->run()
#11 /home/huwaneko/shogi.fun/public_html/niconico/wiki/index.php(46): wfIndexMain()
#12 {main}