Dizin permissionları ile alakalı ciddi probleminiz var
bu izinlerden emin olun ve mod securityi kapatın
root directory : 0755
wp-includes/ : 0755
wp-admin/ : 0755
wp-admin/js/ : 0755
wp-content/ : 0755
wp-content/themes/ : 0755
wp-content/plugins/ : 0755
wp-admin/index.php : 0644
.htaccess : 0644
wp-config.php : 0644