Before adding the extra code to /etc/squirrelmail/config.php I found in /var/log/apache2/error.log :
[Mon May 18 08:45:36.075168 2015] [:error] [pid 24923] [client 92.203.28.105:59703] PHP Fatal error: Call to undefined function session_unregister() in /home/httpd/htdocs/squirrelmail/functions/global.php on line 265, referer: https://localhost/squirrelmail/src/login.php
I forgot:
Before adding the extra code to /etc/squirrelma il/config. php I found in /var/log/ apache2/ error.log :
[Mon May 18 08:45:36.075168 2015] [:error] [pid 24923] [client 92.203. 28.105: 59703] PHP Fatal error: Call to undefined function session_ unregister( ) in /home/httpd/ htdocs/ squirrelmail/ functions/ global. php on line 265, referer: https:/ /localhost/ squirrelmail/ src/login. php