I tried to upgrade from an old 2.7.x (I can't remember exactly the number) to the version 2.8.6 but when I did it, the page leaved blank and when I wanted to access the site it came always on the upgrade.php page.
I also tried a manual upgrade but the problem is still remaining.
What can I do to recover my configuration?
Thanks in advance for any advice.
Piwigo version: 2.7.x
PHP version: 5.6.26
MySQL version: 5.5.50 - MariaDB
Piwigo URL: http://www.golfvuissens-photos.ch