ramonrails said over 6 years ago on WYSIWYG Editor with Summernote :
# config/initializers/refile.rb
Refile.store = Refile::Backend::FileSystem.new(Rails.root.join('public', 'uploads', 'refile_store'))

Maybe this config can be included too in the article. It allows to persist the uploaded attachments properly.

Without this config, the uploads just stay in system tmp or cache folders and eventually get purged.