Instagram ruby gem - Unable to reach callback URL

Been experimenting with the instagram-ruby-gem on and off for a few days - no matter what I do, when a try to create a realtime subscription, I get https://api.instagram.com/v1/subscriptions.json: 400: Unable to reach callback URL - I can always reach the URL with a web browser and I've tried exposing the url with both localtunnel and heroku with no success. Are there other issu开发者_如何学运维es that will produce this same error message? Any other ideas?

def sub
  client = Instagram.client
  client.create_subscription(
    :object => 'tag',
    :callback_url => root_url,
    :aspect => "media",
    :object_id => "pizza"
  )
end

I had the same problem,

In heroku i was using only one dyno and the callback returned 400: Unable to reach callback URL becouse when instagram called back the dyno was busy in the first call (the create subscription call) and returned error. For someone with the same problem i used two dynos and unicorn.

I had the same problem.

Seems that instagram doesn't reach the URLs that returns a blank page.

In my case, the script that receives the call had a syntax error and, with error_reporting=off, gives back an empty page. Once I've fixed the script, instagram starts to reach the URL.

I had the same problem. It worked when I accidentally restarted the router and got another IP assigned. It seems that Instagram might block some subscriptions (and the error message Unable to reach callback URL in that case is really misleading).