Event Registration - Empty Session object when not logged in

Question

I am running Civi 4.6.10 on WP 4.3.2.

I know this sounds like a several other existing questions but I've tried all the suggested solutions and no fix.

When a user is logged in (or even logged out but the system remembers them) the user can register for an event. When I am in an incognito window or a new browser where I have never logged in before, when I press Continue from the first page of the Registration, I get the error "Sorry but we are not able to provide this at the moment. Could not find valid value for id."

I did a bunch of debugging and found the real underlying issue to be that the CRM_Core_Session Object is empty. There is an [entryURL] but no [qfPrivateKey] or [qfSessionID]. When I am logged in (or logged out but recognized by the system) then I see that the CRM_Core_Session Object has both the [qfPrivateKey] and [qfSessionID].

I have verified that my base url in my civicrm.settings.php file does have "http://www.mysite.org" and the URL on the pages have www.

There is an anonymous user role in my Wordpress install and I tested giving it full civi permissions and it did not solve the problem.

In CiviCRM -> System Settings -> CMS Database Integration I set civicrm as the base page and added it as a parent page to my event registration page - didn't help.

The event registration form that I have been testing with was generated from a Wordpress shortcode. If I go directly to the link for the event registration generated from Civi then when I press continue, I don't get an error but it just refreshes the page and I see that the session object is empty.

PLEASE HELP!

Answer 1

After debugging and debugging and searching and searching I called Bluehost. We are on a VPS customized for Wordpress sites that has a "feature" called Varnish Cache. The first thing the guy did was disable this "feature" and voila, my sessions were no longer being destroyed.

Hope this helps someone!