Exception encountered, of type "Error"
[9b9420b9] /index.php?action=export2oo&title=%D0%9E%D0%B1%D1%81%D1%83%D0%B6%D0%B4%D0%B5%D0%BD%D0%B8%D0%B5%3AHardprob%2FMinimum_Stacker_Crane_Problem Error from line 229 of /var/www/discopal/actual/extensions/DocExport/DocExport.php: Call to undefined function wfMessageNoTrans()
Backtrace:
#0 /var/www/discopal/actual/extensions/DocExport/DocExport.php(144): DocExport::sendTo()
#1 /var/www/discopal/actual/includes/Hooks.php(201): DocExport::onUnknownAction()
#2 /var/www/discopal/actual/includes/MediaWiki.php(494): Hooks::run()
#3 /var/www/discopal/actual/includes/MediaWiki.php(287): MediaWiki->performAction()
#4 /var/www/discopal/actual/includes/MediaWiki.php(714): MediaWiki->performRequest()
#5 /var/www/discopal/actual/includes/MediaWiki.php(508): MediaWiki->main()
#6 /var/www/discopal/actual/index.php(41): MediaWiki->run()
#7 {main}