Uninitialized constant for controller concern in Heroku production sstem

[Dragonicity]

I am getting an error when running the app (or using Rails Console) on Heroku where the petergate action_controller finds a missing constant for a concern module:

/app/vendor/bundle/ruby/2.4.0/gems/petergate-1.8.0/lib/petergate/action_controller/base.rb:10:in `const_missing': uninitialized constant ApplicationController::SetI18nLocale (NameError)

This works OK in development and there is no issue with the concern. I tried to add include Petergate::ActionController::Base before the include for the concern in the ApplicationController but this also does not work. I am using Ruby 2.4.1 and Rails 5.1.3. Any suggestions on how to proceed? Thanks.

[Dragonicity]

Sorry, was unrelated to Petergate