CiviCRM Community Forums (archive)

Recently upgraded from CiviCRM 4.0 to 4.1.5, then to 4.2.6 along with upgrade from Joomla 1.6 to 2.5.6 to 2.5.8.  Also migrated, following all the instructions re clearing cache and updating settings, but have a persistent problem.

When registering for events or membership, we've received dozens of reports of members who get a blank screen after entering their information instead of the confirmation screen.  Nothing shows up in Apache error logs, and a white screen appears if I have debugging turned off.  With it turned on, the following backtrace is displayed, but nothing else.

#0 /home/XXX/XXX/administrator/components/com_civicrm/civicrm/CRM/Core/Error.php(305): CRM_Core_Error::backtrace()
#1 /home/XXX/XXX/administrator/components/com_civicrm/civicrm/CRM/Core/Controller.php(251): CRM_Core_Error::fatal("We can't load the requested web page. This page requires cookies to be enable...")
#2 /home/XXX/XXX/administrator/components/com_civicrm/civicrm/CRM/Core/Controller.php(160): CRM_Core_Controller->key("CRM_Event_Controller_Registration", TRUE, FALSE)
#3 /home/XXX/XXX/administrator/components/com_civicrm/civicrm/CRM/Event/Controller/Registration.php(41): CRM_Core_Controller->__construct("Event Registration", "null")
#4 /home/XXX/XXX/administrator/components/com_civicrm/civicrm/CRM/Core/Invoke.php(207) : eval()'d code(1): CRM_Event_Controller_Registration->__construct("Event Registration", TRUE, "null", NULL, "false")
#5 /home/XXX/XXX/administrator/components/com_civicrm/civicrm/CRM/Core/Invoke.php(207): eval()
#6 /home/XXX/XXX/components/com_civicrm/civicrm.php(78): CRM_Core_Invoke::invoke((Array:3))
#7 /home/XXX/XXX/components/com_civicrm/civicrm.php(18): civicrm_invoke()
#8 /home/XXX/XXX/libraries/joomla/application/component/helper.php(383): require_once("/home/XXX/XXX/components/com_civicrm/civicrm.php")
#9 /home/XXX/XXX/libraries/joomla/application/component/helper.php(351): JComponentHelper::executeComponent("/home/XXX/XXX/components/com_civicrm/civicrm.php")
#10 /home/XXX/XXX/includes/application.php(197): JComponentHelper::renderComponent("com_civicrm")
#11 /home/XXX/XXX/index.php(42): JSite->dispatch()
#12 {main}

I would love to at least have an appropriate error message display instead of a blank screen, but don't know what else to try!

I've followed all the steps in the migration manual, verified Base_URL and all configuration settings, etc, but I must be missing something somewhere!