Thank you page does not appear - Could not find valid value for id

Question

After updating to 5.44 I get in my installation (wordpress) "Could not find valid value for id" when the thank you page is called. In Wordpress a "Basepage" is created, the registration also comes through and is entered in the database. Until the beginning of December this always worked. The following error message appears:

CRM_Core_Exception: Konnte keinen gültigen Wert für id finden. in ../httpdocs/wp-content/plugins/civicrm/civicrm/CRM/Event/StateMachine/Registration.php on line 27
Exception trace
#   Function    Location
0   CRM_Utils_Request::retrieve()   ../httpdocs/wp-content/plugins/civicrm/civicrm/CRM/Event/StateMachine/Registration.php:27
1   CRM_Event_StateMachine_Registration->__construct()  ../httpdocs/wp-content/plugins/civicrm/civicrm/CRM/Event/Controller/Registration.php:27
2   CRM_Event_Controller_Registration->__construct()    ../httpdocs/wp-content/plugins/civicrm/civicrm/CRM/Core/Invoke.php:308
3   CRM_Core_Invoke::runItem()  ../httpdocs/wp-content/plugins/civicrm/civicrm/CRM/Core/Invoke.php:69
4   CRM_Core_Invoke::_invoke()  ../httpdocs/wp-content/plugins/civicrm/civicrm/CRM/Core/Invoke.php:36
5   CRM_Core_Invoke::invoke()   ../httpdocs/wp-content/plugins/civicrm/civicrm.php:1169
6   CiviCRM_For_WordPress->invoke() ../httpdocs/wp-content/plugins/civicrm/includes/civicrm.basepage.php:366
7   CiviCRM_For_WordPress_Basepage->basepage_handler()  ../httpdocs/wp-includes/class-wp-hook.php:303
8   WP_Hook->apply_filters()    ../httpdocs/wp-includes/class-wp-hook.php:327
9   WP_Hook->do_action()    ../httpdocs/wp-includes/plugin.php:518
10  do_action_ref_array()   ../httpdocs/wp-includes/class-wp.php:763
11  WP->main()  ../httpdocs/wp-includes/functions.php:1291
12  wp()    ../httpdocs/wp-blog-header.php:16
13  require('/var/www/vhosts/…')    ../httpdocs/index.php:17
14  {main}

Answer 1

I just experienced the same issue after updating to 5.45.1. This particular site has had CiviCRM installed for a long time. It was never switched to utilize clean URLs. Once I implemented clean URLs the we no longer get the error.

More info on clean URLs can be found here: https://docs.civicrm.org/sysadmin/en/latest/integration/wordpress/clean-urls/