Thread:Project:Support desk/Mediawiki internal error: Another module has already been registered as oojs (ResourceLoader.php)

I just tried to upgrade Mediawiki from 1.22 to 1.24.1.

Everything seemed to go smoothly till I tried loading the site and got an error about oojs already being registered. Did the requisite googling and didn't find anything that seemed to fit or provide options to fix. I've attached the output below. Things to look at?

MediaWiki internal error.

Original exception: [f164743a] /wiki/index.php?title=Main_Page Exception from line 279 of /usr/local/var/www/mediawiki-1.24.1/includes/resourceloader/ResourceLoader.php: ResourceLoader duplicate registration error. Another module has already been registered as oojs Backtrace:
 * 1) 0 /usr/local/var/www/mediawiki-1.24.1/includes/resourceloader/ResourceLoader.php(240): ResourceLoader->register(array)
 * 2) 1 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(2730): ResourceLoader->__construct(GlobalVarConfig)
 * 3) 2 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(526): OutputPage->getResourceLoader
 * 4) 3 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(552): OutputPage->filterModules(array, string)
 * 5) 4 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(624): OutputPage->getModules(boolean, string, string)
 * 6) 5 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(3039): OutputPage->getModuleMessages(boolean, string)
 * 7) 6 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(3114): OutputPage->getScriptsForBottomQueue(boolean)
 * 8) 7 /usr/local/var/www/mediawiki-1.24.1/includes/skins/Skin.php(618): OutputPage->getBottomScripts
 * 9) 8 /usr/local/var/www/mediawiki-1.24.1/includes/skins/SkinTemplate.php(490): Skin->bottomScripts
 * 10) 9 /usr/local/var/www/mediawiki-1.24.1/includes/skins/SkinTemplate.php(274): SkinTemplate->prepareQuickTemplate(OutputPage)
 * 11) 10 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(2226): SkinTemplate->outputPage
 * 12) 11 /usr/local/var/www/mediawiki-1.24.1/includes/MediaWiki.php(594): OutputPage->output
 * 13) 12 /usr/local/var/www/mediawiki-1.24.1/includes/MediaWiki.php(435): MediaWiki->main
 * 14) 13 /usr/local/var/www/mediawiki-1.24.1/index.php(46): MediaWiki->run
 * 15) 14 {main}

Exception caught inside exception handler: [23e4344c] /wiki/index.php?title=Main_Page Exception from line 279 of /usr/local/var/www/mediawiki-1.24.1/includes/resourceloader/ResourceLoader.php: ResourceLoader duplicate registration error. Another module has already been registered as oojs Backtrace:
 * 1) 0 /usr/local/var/www/mediawiki-1.24.1/includes/resourceloader/ResourceLoader.php(240): ResourceLoader->register(array)
 * 2) 1 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(2730): ResourceLoader->__construct(GlobalVarConfig)
 * 3) 2 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(526): OutputPage->getResourceLoader
 * 4) 3 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(552): OutputPage->filterModules(array, string)
 * 5) 4 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(624): OutputPage->getModules(boolean, string, string)
 * 6) 5 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(3039): OutputPage->getModuleMessages(boolean, string)
 * 7) 6 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(3114): OutputPage->getScriptsForBottomQueue(boolean)
 * 8) 7 /usr/local/var/www/mediawiki-1.24.1/includes/skins/Skin.php(618): OutputPage->getBottomScripts
 * 9) 8 /usr/local/var/www/mediawiki-1.24.1/includes/skins/SkinTemplate.php(490): Skin->bottomScripts
 * 10) 9 /usr/local/var/www/mediawiki-1.24.1/includes/skins/SkinTemplate.php(274): SkinTemplate->prepareQuickTemplate(OutputPage)
 * 11) 10 /usr/local/var/www/mediawiki-1.24.1/includes/OutputPage.php(2226): SkinTemplate->outputPage
 * 12) 11 /usr/local/var/www/mediawiki-1.24.1/includes/exception/MWException.php(195): OutputPage->output
 * 13) 12 /usr/local/var/www/mediawiki-1.24.1/includes/exception/MWException.php(238): MWException->reportHTML
 * 14) 13 /usr/local/var/www/mediawiki-1.24.1/includes/exception/MWExceptionHandler.php(45): MWException->report
 * 15) 14 /usr/local/var/www/mediawiki-1.24.1/includes/exception/MWExceptionHandler.php(141): MWExceptionHandler::report(MWException)
 * 16) 15 /usr/local/var/www/mediawiki-1.24.1/includes/MediaWiki.php(449): MWExceptionHandler::handle(MWException)
 * 17) 16 /usr/local/var/www/mediawiki-1.24.1/index.php(46): MediaWiki->run
 * 18) 17 {main}