Rails - SendGrid - invalid response error

Question

I'm using SendGrid for my Rails App on Heroku. I tested the process of signing up. I saw the email get created and sent in SendGrid. The email showed up in my gmail inbox. But when I clicked the "Activate" link in the email I get the error below. After I got the email and clicked the link I noticed that even though I only clicked it a few times a long list of "clicked" activities showed up in sendgrid. I noticed that each click seemed to generate three "clicked" activities in sendgrid. don't know if that's a clue or not.

sendgrid.net sent an invalid response. ERR_INVALID_REDIRECT

Answer 1

Make sure your host name is correct in production environment.

config/environments/production.rb

Rails.application.configure do
.
.
host = 'your heroku app.herokuapp.com'
.
.
end

like this:
host = 'https://fierce-wave.herokuapp.com'