I tried to use http://commons.wikimedia.beta.wmflabs.org/wiki/Special:GWToolset with User:Léna but found the following error message (I guess related to the "é" in my user name ?)
[cef046e1] /wiki/Special:GWToolset MWException from line 406 of /srv/mediawiki/php-master/extensions/GWToolset/includes/Helpers/GWTFileBackend.php: <p>Please contact a developer. This issue must be addressed before you can continue. Please add the following text to your report:
</p><p>GWToolset\Helpers\GWTFileBackend::saveFile: Could not create directory "mwstore://gwtoolset-backend/gwtoolset-metadata/Léna/d/3/f".
</p>
Backtrace:
#0 /srv/mediawiki/php-master/extensions/GWToolset/includes/Handlers/UploadHandler.php(642): GWToolset\Helpers\GWTFileBackend->saveFile(Php\File)
#1 /srv/mediawiki/php-master/extensions/GWToolset/includes/Handlers/Forms/MetadataDetectHandler.php(204): GWToolset\Handlers\UploadHandler->saveMetadataToFileBackend()
#2 /srv/mediawiki/php-master/extensions/GWToolset/includes/Handlers/Forms/FormHandler.php(176): GWToolset\Handlers\Forms\MetadataDetectHandler->processRequest()
#3 /srv/mediawiki/php-master/extensions/GWToolset/includes/Specials/SpecialGWToolset.php(119): GWToolset\Handlers\Forms\FormHandler->execute()
#4 /srv/mediawiki/php-master/extensions/GWToolset/includes/Specials/SpecialGWToolset.php(72): GWToolset\SpecialGWToolset->processRequest()
#5 /srv/mediawiki/php-master/includes/specialpage/SpecialPage.php(363): GWToolset\SpecialGWToolset->execute(NULL)
#6 /srv/mediawiki/php-master/includes/specialpage/SpecialPageFactory.php(589): SpecialPage->run(NULL)
#7 /srv/mediawiki/php-master/includes/MediaWiki.php(275): SpecialPageFactory::executePath(Title, RequestContext)
#8 /srv/mediawiki/php-master/includes/MediaWiki.php(584): MediaWiki->performRequest()
#9 /srv/mediawiki/php-master/includes/MediaWiki.php(435): MediaWiki->main()
#10 /srv/mediawiki/php-master/index.php(46): MediaWiki->run()
#11 /srv/mediawiki/w/index.php(3): include(string)
#12 {main}