Events and contributions do not submit after upgrade to 4.2.4

After upgrading from 4.2.1 to 4.2.4 all the forms (events and contribution/memberships) generate the same error on submission:
Sorry but we are not able to provide this at the moment.
Could not find valid value for id

url displayed presenting error does not reveal event id:
http://xxx/index.php?option=com_civicrm&task=civicrm/event/register

in the log creating error: for events
Invalid argument supplied for foreach() in /components/com_civicrm/civicrm/CRM/Core/Error.php on line 522
and on contribution:Undefined variable: infoUrl in /components/com_civicrm/civicrm/CRM/Event/Form/Registration.php on line 1373