Les permissions sur /web sont ok mais là j'ai vraiment un autre soucis c'est que je ne vois plus rien du tout!!!
voici les derniers logs apache que j'ai pu récupérer :
Pour info, j'ai modifié aucun fichier, juste vider le cache par FTP au lieu de par l'admin...
[Wed Oct 29 17:51:37 2014] [error] [client 212.24.192.21] PHP Fatal error: Uncaught exception 'Symfony\\Component\\Filesystem\\Exception\\IOException' with message 'Failed to create /home/www/ca4cbb1be7417096998d92c53a7a5cb4/web/NEWSITE/web/assets/backOffice/default/Tinymce.tmp/css' in /home/www/ca4cbb1be7417096998d92c53a7a5cb4/web/NEWSITE/core/vendor/symfony/filesystem/Symfony/Component/Filesystem/Filesystem.php:81\nStack trace:\n#0 /home/www/ca4cbb1be7417096998d92c53a7a5cb4/web/NEWSITE/core/lib/Thelia/Core/Template/Assets/AsseticAssetManager.php(99): Symfony\\Component\\Filesystem\\Filesystem->mkdir('/home/www/ca4cb...', 511)\n#1 /home/www/ca4cbb1be7417096998d92c53a7a5cb4/web/NEWSITE/core/lib/Thelia/Core/Template/Assets/AsseticAssetManager.php(168): Thelia\\Core\\Template\\Assets\\AsseticAssetManager->copyAssets(Object(Symfony\\Component\\Filesystem\\Filesystem), '/home/www/ca4cb...', '/home/www/ca4cb...')\n#2 /home/www/ca4cbb1be7417096998d92c53a7a5cb4/web/NEWSITE/core/lib/Thelia/Core/Template/Smarty/Assets/SmartyAssetsManager.php(76): Thelia\\Core\\Template\\Assets\\AsseticAssetManager->prepareAssets( in /home/www/ca4cbb1be7417096998d92c53a7a5cb4/web/NEWSITE/core/vendor/symfony/filesystem/Symfony/Component/Filesystem/Filesystem.php on line 81
[Wed Oct 29 17:51:11 2014] [error] [client 90.40.30.36] File does not exist: /home/www/ca4cbb1be7417096998d92c53a7a5cb4/web/favicon.ico, referer: http://www.bylea.com/fr/
[Wed Oct 29 17:50:05 2014] [error] [client 212.24.192.21] Symbolic link not allowed or link target not accessible: /home/www/ca4cbb1be7417096998d92c53a7a5cb4/web/NEWSITE/web/cache/images/product/collier_arabesqu_4c31ad4d56974-23.jpg, referer: http://www.bylea.com/NEWSITE/web/_index
[Wed Oct 29 17:50:05 2014] [error] [client 212.24.192.21] Symbolic link not allowed or link target not accessible: /home/www/ca4cbb1be7417096998d92c53a7a5cb4/web/NEWSITE/web/cache/images/product/11413aae196a66dae416fdbe05d597a3-bague-tahiti-or-jaune-28-32.jpg, referer: http://www.bylea.com/NEWSITE/web/_index
[Wed Oct 29 17:50:05 2014] [error] [client 212.24.192.21] Symbolic link not allowed or link target not accessible: /home/www/ca4cbb1be7417096998d92c53a7a5cb4/web/NEWSITE/web/cache/images/product/bagueargentetamthyste.jpg-30.jpg, referer: http://www.bylea.com/NEWSITE/web/_index
[Tue Oct 28 22:56:50 2014] [error] [client 193.252.118.164] Negotiation: discovered file(s) matching request: /home/www/ca4cbb1be7417096998d92c53a7a5cb4/web/robots.txt (None could be negotiated).