exception_notification gem raises ActionView::Template::Error (code converter not found (UTF-8 to UTF-16)) only on Heroku production mode

Question

I create rails app deployed on Heroku. also, exception_notification gem enabled.

when it is on development setup ActionMailer to Gmail, everything is fine and sends a notification from Gmail address.

but when it comes to production environment on Heroku, I get following error when server trying to send a email.

ActionView::Template::Error (code converter not found (UTF-8 to UTF-16))

Could anyone tell me what's happening here?

Answer 1

The issue was raised on the main repository (see here), but so far was not addressed.

You might want to take a look at this fork to the exception_notification gem, specifically this commit which tries to deal with the problem: https://github.com/alanjds/exception_notification/commit/048fc6be972189e62ca3b9453d19233ec5773016

To use this fork I pointed the gem to it, like so:

Gemfile:

gem 'exception_notification', git: 'git://github.com/alanjds/exception_notification.git'

This solved the issue for me.