Internal error

From SMC Wiki

[7c5056d41d2dff591d553583] /index.php?title=%25E0%25B4%25AB%25E0%25B5%258B%25E0%25B4%25B0%25E0%25B5%258D%25E2%2580%258D%25E0%25B4%259A%25E0%25B5%258D%25E0%25B4%25AF%25E0%25B5%2582%25E0%25B4%25A3%25E0%25B5%258D%25E2%2580%258D_%25E0%25B4%25AE%25E0%25B4%25B2%25E0%25B4%25AF%25E0%25B4%25BE%25E0%25B4%25B3%25E0%25B4%2582&diff=next&oldid=1461 Error: Call to a member function getUser() on null

Backtrace:

from /var/www/wiki.smc.org.in/includes/diff/DifferenceEngine.php(1677)
#0 /var/www/wiki.smc.org.in/includes/diff/DifferenceEngine.php(1204): DifferenceEngine->getMultiNotice()
#1 /var/www/wiki.smc.org.in/includes/diff/DifferenceEngine.php(1159): DifferenceEngine->getDiff()
#2 /var/www/wiki.smc.org.in/includes/diff/DifferenceEngine.php(922): DifferenceEngine->showDiff()
#3 /var/www/wiki.smc.org.in/includes/page/Article.php(952): DifferenceEngine->showDiffPage()
#4 /var/www/wiki.smc.org.in/includes/page/Article.php(486): Article->showDiffPage()
#5 /var/www/wiki.smc.org.in/includes/actions/ViewAction.php(78): Article->view()
#6 /var/www/wiki.smc.org.in/includes/MediaWiki.php(556): ViewAction->show()
#7 /var/www/wiki.smc.org.in/includes/MediaWiki.php(333): MediaWiki->performAction()
#8 /var/www/wiki.smc.org.in/includes/MediaWiki.php(923): MediaWiki->performRequest()
#9 /var/www/wiki.smc.org.in/includes/MediaWiki.php(576): MediaWiki->main()
#10 /var/www/wiki.smc.org.in/index.php(50): MediaWiki->run()
#11 /var/www/wiki.smc.org.in/index.php(46): wfIndexMain()
#12 {main}