Here is the error from the Apache error logs:
session_destroy(): Trying to destroy uninitialized session in /var/www/prosper202/202-access-denied.php on line 8, referer: http://mydomain.org/202-login.php?re...202-account%2F
I searched a lot but I didn't find any solution yet!
I am using VPS hosting from Digital Ocean.
Thank you for your help!