Drupal 8.5.3, all modules and themes up to date.
The CKEditor only shows up for administrator users when creating or editing nodes. The authorized users are listed as Roles for the Text Format "Basic HTML" which is the Text Format for the field in the Content Type too.
There is a javascript error being thrown in /core/modules/ckeditor/js/cheditor.js, line 134 saying "drupalSettings.ckeditor" is undefined.
Thanks, Greg