I am trying to delete several event registrations from an event, but each time I try with any of the contacts it fails. I get a pop-up warning that any corresponding payment transactions will be deleted and I click the tick/delete button but then I just get the spinning Civi logo and the webpage hangs like that.

The event registrations were created using a webform registering multiple people (parent and children) for the event at once. I turned on logging errors to the Drupal logs but there is nothing appearing there. When I refresh the webpage the participant listing is the same as before.

I can edit the participants and change their status to cancelled but cannot delete the registration. We're on Civi 4.6.5 and Drupal 7 with CiviHosting.

EDIT: I get this error message following @petednz advice:

Fatal error: Class name must be a valid object or a string in /home/../www/www/includes/common.inc on line 7963

Line 7963 is in bold below:

* Gets the entity controller for an entity type.
* @return DrupalEntityControllerInterface
* The entity controller object for the specified entity type.
function entity_get_controller($entity_type) {
$controllers = &drupal_static(FUNCTION, array());
if (!isset($controllers[$entity_type])) {
$type_info = entity_get_info($entity_type);
$class = $type_info['controller class'];
$controllers[$entity_type] = new $class($entity_type);
return $controllers[$entity_type];

This Drupal post is another recent user with error at the same line but different situation:

Viewing entity results in Fatal error: Class name must be a valid object or a string

  • 1
    Not so much as an answer but some more useful info. if you right click on the delete link and instead open the screen as a page instead of a pop up, I can see Fatal error: Class name must be a valid object or a string in <oursite>/includes/common.inc on line 796
    – petednz - fuzion
    Aug 7, 2015 at 5:12
  • Thanks. Have updated the description above with the problem code.
    – Phil Hart
    Aug 8, 2015 at 7:30

3 Answers 3


Update to the latest version of civicrm_entity

  • Bingo. Upgrade to 7.x-2.0-beta1 for civicrm_entity fixed this issue. Upgrade to Civi 4.6.6 fixed a related issue with viewing participants of 'Registered' status.
    – Phil Hart
    Aug 13, 2015 at 4:01

This could be a JavaScript error. Perhaps something conflicting. If there is nothing in your server logs you could try opening your web browser's development console (normally F12) and then run through the process. Do you see any JS errors reported there?


I'm on the Drupal 6 version of 4.6.7 and also cannot delete an event registrant. Also get the spinning wheel.

This is my error:

Fatal error: require_once(): Failed opening required 'api/v2/Participant.php' (include_path='/home/purcosa/public_html/sites/default/files/civicrm/custom_extensions/civiexportexcel/:/home/purcosa/public_html/sites/default/files/civicrm/custom_extensions/nz.co.fuzion.civitoken/:/home/purcosa/public_html/sites/default/files/civicrm/custom_extensions/orgdedupe/:/home/purcosa/public_html/sites/default/files/civicrm/custom_extensions/com.pogstone.contenttokens/:/home/purcosa/public_html/sites/default/files/civicrm/custom_extensions/nz.co.fuzion.extendedreport-master/:/home/purcosa/public_html/sites/default/files/civicrm/custom_extensions/com.pogstone.fancytokens-3.2/:/home/purcosa/public_html/sites/default/files/civicrm/custom_extensions/org.civicrm.module.cividiscount-3.0/:/home/purcosa/public_html/sites/default/files/civicrm/custom_extensions/com.pogstone.fancysearches-master/:/home/purcosa/public_html/sites/default/files/civicrm/custom_extensions/noverwrite-master/:/home/purcosa/public_html/sites/default/files/civicrm/custo in /home/purcosa/public_html/sites/all/modules/ckeditor_link/civievent_discount/civievent_discount.admin.inc on line 764

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