Exception encountered, of type "Error"
[1330ee7552133121fe543432] /pvv/Special:UserMerge Error from line 23 of /usr/local/www/mediawiki/extensions/UserMerge/UserMerge_body.php: Call to undefined function wfLoadExtensionMessages()
Backtrace:
#0 /usr/local/www/mediawiki/includes/specialpage/SpecialPage.php(479): UserMerge->execute(NULL)
#1 /usr/local/www/mediawiki/includes/specialpage/SpecialPageFactory.php(577): SpecialPage->run(NULL)
#2 /usr/local/www/mediawiki/includes/MediaWiki.php(282): SpecialPageFactory::executePath(Title, RequestContext)
#3 /usr/local/www/mediawiki/includes/MediaWiki.php(735): MediaWiki->performRequest()
#4 /usr/local/www/mediawiki/includes/MediaWiki.php(509): MediaWiki->main()
#5 /usr/local/www/mediawiki/index.php(43): MediaWiki->run()
#6 {main}