I have a site which has been running for some time. Recently whenever anyone makes a contribution (via PayPal). When they click return to merchant they get the following error:


This is caused by the qfKey coming back in the URL being invalid. The error starts on line 308 of civicrm/CRM/Core/Controller.php and is caused by CRM_Core_Key::validate($key, $name, $addSequence) returning null.

I have disabling all my custom templates and the issue persists. Looking at the code it should get the qfKey from the request, so what is causing it to be invalid?

  • Do you have cookies enabled? Are you creating any user while submitting the contribution? Mar 20 at 10:37
  • Cookies are enabled, I can see a PHPSESSID being set. Yes a user is being created when the submission is taking place. Mar 20 at 10:58
  • You have an interesting point disabling the account creation is enough to fix the problem. Although not ideal Mar 20 at 12:37

This usually happens when you have

  1. Browser cookies disabled
  2. CiviCRM cache cleared when users is on payment processor gateway and doing payment.
  3. User is created at the time of submitting contribution and causes session to clear.
  • Yes it appears that number 3 is my issue, is there any way to fix this though? Mar 23 at 11:12

I have had a similar problem, but it involves existing users not created users. See my question for a description and solution.

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