Try waiting a few minutes and reloading.
(Cannot access the database: Connection refused (mysql.db.huma-num.fr))
Backtrace:
#0 /sites/polima/www/web_main/w/includes/libs/rdbms/loadbalancer/LoadBalancer.php(1140): Wikimedia\Rdbms\Database->reportConnectionError('Connection refu...') #1 /sites/polima/www/web_main/w/includes/libs/rdbms/loadbalancer/LoadBalancer.php(750): Wikimedia\Rdbms\LoadBalancer->reportConnectionError() #2 /sites/polima/www/web_main/w/includes/GlobalFunctions.php(2813): Wikimedia\Rdbms\LoadBalancer->getConnection(0, Array, false) #3 /sites/polima/www/web_main/w/includes/cache/MessageCache.php(463): wfGetDB(-1, 'api') #4 /sites/polima/www/web_main/w/includes/cache/MessageCache.php(418): MessageCache->loadFromDB('fr', NULL) #5 /sites/polima/www/web_main/w/includes/cache/MessageCache.php(342): MessageCache->loadFromDBWithLock('fr', Array, NULL) #6 /sites/polima/www/web_main/w/includes/cache/MessageCache.php(971): MessageCache->load('fr') #7 /sites/polima/www/web_main/w/includes/cache/MessageCache.php(899): MessageCache->getMsgFromNamespace('Mainpage', 'fr') #8 /sites/polima/www/web_main/w/includes/cache/MessageCache.php(868): MessageCache->getMessageForLang(Object(Language), 'mainpage', true, Array) #9 /sites/polima/www/web_main/w/includes/cache/MessageCache.php(808): MessageCache->getMessageFromFallbackChain(Object(Language), 'mainpage', true) #10 /sites/polima/www/web_main/w/includes/Message.php(1290): MessageCache->get('mainpage', true, Object(Language)) #11 /sites/polima/www/web_main/w/includes/Message.php(842): Message->fetchMessage() #12 /sites/polima/www/web_main/w/includes/Message.php(934): Message->toString('text') #13 /sites/polima/www/web_main/w/includes/Title.php(587): Message->text() #14 /sites/polima/www/web_main/w/includes/MediaWiki.php(121): Title::newMainPage() #15 /sites/polima/www/web_main/w/includes/MediaWiki.php(141): MediaWiki->parseTitle() #16 /sites/polima/www/web_main/w/includes/MediaWiki.php(780): MediaWiki->getTitle() #17 /sites/polima/www/web_main/w/includes/MediaWiki.php(524): MediaWiki->main() #18 /sites/polima/www/web_main/w/index.php(42): MediaWiki->run() #19 {main}