Everytime I try to make an event, or access any page with event information, I get the following error:

You have requested a non-existent service "civi_flexmailer_required_tokens".

Using latest Civi 5, Wordpress 4.9

4 Answers 4


I had this problem after upgrading from Drupal 8 to 9 and upgrading Civi to 5.51.1. Thanks to @seamuslee on Mattermost for solving this issue for me. These are the steps I followed on a Drupal installation to fix it:

  1. Disable Mosaico in Extensions
  2. Disable Flexmailer in Extensions
  3. Delete the Flexmailer extension directory (/sites/default/files/civicrm/ext/org.civicrm.flexmailer)
  4. Clear Civi caches and rebuild paths/menus at /civicrm/admin/setting/updateConfigBackend?reset=1
  5. Enable Flexmailer in Extensions
  6. Enable Mosaico in Extensions

This issue is also answered at CiviCRM core now includes Flexmailer: how to remove old flexmailer extension?

  • that rocks! thanks Ben and Seamus Sep 15, 2022 at 16:10

we have similar issue but after clearing civicrm cache using menu/rebuild it started working.

  • For drupal civicrm/menu/rebuild?reset=1 Jun 18, 2018 at 22:53

We were seeing the same problem after upgrade to CiviCRM 5.0.2. This is a detail follow-up on Sunil's answer above (sorry, didn't have enough reputation points to comment on his directly and thought this would be useful.)...

The URL to clear the CiviCRM Cache is:



Still figuring this out - but disabling Event Calendar (com.osseed.eventcalendar) fixed the issue.

Update: Cleaned up Cache - error persisted, Cleaned up cache and rebuilt CiviCRM menu - re-enabled com.oosseed.eventcalendar - all good to go.

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