omniauth-facebook issues "Invalid_Credentials" - ruby-on-rails-3

Question

I have a very strange problem, but only at production server.
I was using this Gem in my Gemfile.
gem "omniauth-facebook", "~> 1.4.1"
But suddenly started getting the following error on production, works fine at local.
heroku[router]: at=info method=GET path=/auth/failure?message=invalid_credentials&strategy=facebook host=www.myapp.com fwd="182.189.55.111" dyno=web.1 queue=0 wait=0ms connect=1ms service=90ms status=302 bytes=95
Searched around different forums and people says, a temporary solution is just to revert back to 1.4.0 version i.e.
gem "omniauth-facebook", "1.4.0"
It also works fine at local but started getting another error message at production.
OmniAuth::Strategies::Facebook::NoAuthorizationCodeError (must pass either a `code` parameter or a signed request (via `signed_request` parameter or a `fbsr_XXX` cookie)):
this link says to upgrade again to this version 1.4.1
Seems to a be deadlock/looping situation here. Can anybody faced/fixed this issue?
Thanks in advance.

Answer 1

I assume you are using the JS SDK to login? Maybe your code looks something like:
if (response.authResponse) {
var url = "/auth/facebook/callback";
window.location = url;
}
I'm not sure why the signed request isn't being passed along automatically, but I've found this workaround to work fine:
if (response.authResponse) {
var url = "/auth/facebook/callback";
url += '&' + $.param({ signed_request: response.authResponse.signedRequest });
window.location = url;
}