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