Topic on Project:Support desk

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}

I don't know of the exact internals, but this error means that the OOjs module has tried to be registered multiple times. I would guess that this can happen, if you use old extensions or an old skin, which are not properly updated for MediaWiki 1.24. Maybe you still have files from the old MediaWiki version in the way, which are now causing trouble. In this case updating them should solve the issue.

In order to investigate, which extension might cause this, you might try disabling all extensions and then enabling them one by one until you get the error again!

Thanks, that was it. I need do do a serious cleanup of the extensions directory instead of just bulk copying during the backup. But, I'm up and running now.

Thanks again.