If you are unable to login after you have upgraded.
Checkout this link
if that doesnt work try adding the following line to your settings.php
ini_set('session.cookie_domain', '.example.com');
Drupal CMS Web Development
If you are unable to login after you have upgraded.
Checkout this link
if that doesnt work try adding the following line to your settings.php
ini_set('session.cookie_domain', '.example.com');