Answers.Body: <p>Composer 2.5.1, just released, fixed this. Run <code>composer self-update</code>, then <code>composer install</code> on the site to update the class loader.</p>
  <p><a href="https://lab.civicrm.org/dev/core/-/issues/4046" rel="nofollow noreferrer">Composer 2.5 is not compatible with civi, yet</a>. Use <code>composer self-update --rollback</code> for now; then run <code>composer install</code> again on your site.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-12-23T00:49:31.960Z
Answers.LastActivityDate: 2023-05-03T07:01:29.843Z
Answers.LastEditDate: 2023-05-03T07:01:29.843Z
Answers.UserDisplayName: Demerit
Body: <p>After installing the latest version of CiviCRM (5.56.1) I cannot open my website anymore and log is showing this message:</p>
  <p>Got error 'PHP message: Uncaught PHP Exception Exception: &quot;Serialization of 'Closure' is not allowed&quot; at /data/sites/web/instituutvlaamsevolkskunstbe/cms-install/4466-instituut-voor-vlaamse-volkskunst/production/vendor/civicrm/civicrm-core/CRM/Extension/ClassLoader.php line 85'</p>
  <p>and drush cr returns:</p>
  <p>Serialization of 'Closure' is not allowed</p>
  <p>Drupal version 9.5.0
  PHP version 7.4.33</p>
  <p>I cannot find anything related</p>
  <p>Thanks,
  Stefaan</p>
  
Tags: <drupal>
Title: Serialization of 'Closure' is not allowed at classloader.php
ThreadText: # Serialization of 'Closure' is not allowed at classloader.php
  
  (Asked by: username_0 on 2022-12-22)
  
  After installing the latest version of CiviCRM (5.56.1) I cannot open my website anymore and log is showing this message:
  
  Got error 'PHP message: Uncaught PHP Exception Exception: "Serialization of 'Closure' is not allowed" at /data/sites/web/instituutvlaamsevolkskunstbe/cms-install/4466-instituut-voor-vlaamse-volkskunst/production/vendor/civicrm/civicrm-core/CRM/Extension/ClassLoader.php line 85'
  
  and drush cr returns:
  
  Serialization of 'Closure' is not allowed
  
  Drupal version 9.5.0
  PHP version 7.4.33
  
  I cannot find anything related
  
  Thanks,
  username_0
  
  **Tags:** drupal
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2022-12-23. Score: 3 | Accepted answer
  
  Composer 2.5.1, just released, fixed this. Run `composer self-update`, then `composer install` on the site to update the class loader.
  
  [Composer 2.5 is not compatible with civi, yet](https://lab.civicrm.org/dev/core/-/issues/4046). Use `composer self-update --rollback` for now; then run `composer install` again on your site.
  
  
  ---
  
  