Error message

• Notice: Undefined index: 0 in user_node_load() (line 3697 of /var/www/drupal/modules/user/user.module).
• Notice: Trying to get property of non-object in user_node_load() (line 3697 of /var/www/drupal/modules/user/user.module).
• Notice: Undefined index: 0 in user_node_load() (line 3698 of /var/www/drupal/modules/user/user.module).
• Notice: Trying to get property of non-object in user_node_load() (line 3698 of /var/www/drupal/modules/user/user.module).
• Notice: Undefined index: 0 in user_node_load() (line 3699 of /var/www/drupal/modules/user/user.module).
• Notice: Trying to get property of non-object in user_node_load() (line 3699 of /var/www/drupal/modules/user/user.module).