CiviEvent - Fatal error when registering: Could not find valid value for id

Question

I have a simple and largely up to date Wordpress 6.02/Civi 5.53 site running registrations for a single paid event. I'm taking payments using the Stripe extension. It couldn't get much more straightforward.

However I'm seeing an error "Could not find valid value for id" that is stopping some people from registering.

I've checked through other posts here on this issue, including:

CiviEvent - Error when registering: Could not find valid value for id

and

"Could not find valid value for id" after event registration on WordPress 5.9.1 and CiviCRM 5.47.2

and I can't see anything wrong with my set-up. Clean URLs, base page, permalinks are all good. I'm not using a shortcode for the event registration form.

It looks like the majority of registrations are working fine, but I've had a few people get in touch reporting the error.

Here's what gets logged:

$Fatal Error Details = array:3 [
  "message" => "Could not find valid value for id"
  "code" => null
  "exception" => CRM_Core_Exception {#6388
    -errorData: array:1 [
      "error_code" => 0
    ]
    #cause: null
    -_trace: null
    #message: "Could not find valid value for id"
    #code: 0
    #file: "/home/wf/sites/default/wp-content/plugins/civicrm/civicrm/CRM/Utils/Request.php"
    #line: 98
    trace: {
      /home/wf/sites/default/wp-content/plugins/civicrm/civicrm/CRM/Utils/Request.php:98 {
        ?~@? if (!isset($value) && $abort) {
        ?~@?   throw new CRM_Core_Exception(ts('Could not find valid value for %1', [1 => $name]));
        ?~@? }
      }
      /home/wf/sites/default/wp-content/plugins/civicrm/civicrm/CRM/Event/StateMachine/Registration.php:27 { ?~@?}
      /home/wf/sites/default/wp-content/plugins/civicrm/civicrm/CRM/Event/Controller/Registration.php:27 { ?~@?}
      /home/wf/sites/default/wp-content/plugins/civicrm/civicrm/CRM/Core/Invoke.php:314 { ?~@?}
      /home/wf/sites/default/wp-content/plugins/civicrm/civicrm/CRM/Core/Invoke.php:69 { ?~@?}
      /home/wf/sites/default/wp-content/plugins/civicrm/civicrm/CRM/Core/Invoke.php:36 { ?~@?}
      /home/wf/sites/default/wp-content/plugins/civicrm/civicrm.php:1199 { ?~@?}
      /home/wf/sites/default/wp-content/plugins/civicrm/includes/civicrm.basepage.php:380 { ?~@?}
      /home/wf/sites/default/wp-includes/class-wp-hook.php:307 { ?~@?}
      /home/wf/sites/default/wp-includes/class-wp-hook.php:331 { ?~@?}
      /home/wf/sites/default/wp-includes/plugin.php:524 { ?~@?}
      /home/wf/sites/default/wp-includes/class-wp.php:787 { ?~@?}
      /home/wf/sites/default/wp-includes/functions.php:1330 { ?~@?}
      /home/wf/sites/default/wp-blog-header.php:16 { ?~@?}
      /home/wf/sites/default/index.php:17 { ?~@?}
    }
  }
]

I'm now at a loss as to how to begin resolving this.

Answer 1

Can you check your civicrm.settings.php have exact below code for clean url?

if (!defined('CIVICRM_CLEANURL')) {
  if (function_exists('variable_get') && variable_get('clean_url', '0') != '0') {
    define('CIVICRM_CLEANURL', 1 );
  }
  elseif ( function_exists('config_get') && config_get('system.core', 'clean_url') != 0) {
    define('CIVICRM_CLEANURL', 1 );
  }
  elseif( function_exists('get_option') && get_option('permalink_structure') != '' ) {
    define('CIVICRM_CLEANURL', 1 );
  }
  else {
    define('CIVICRM_CLEANURL', 0);
  }
}