After upgrading from 4.6.12 to 4.7.1 (with Drupal 7.42), I get the following message when I go to CiviCRM :
CiviCRM_API3_Exception : DB Error: no such field dans civicrm_api3() (ligne 45 dans /home/parst/public_html/drupal/sites/all/modules/civicrm/api/api.php).
(in french)
... and cannot access to CiviCRM