"Page not found" when a user clicks on a Facebook invite from my application

Question

I'm not sure if this is a programming related problem or not, but as I have no experience with the Facebook SDK I'm just assuming that I did something wrong somewhere, even though I've followed the documentation to the T.

I am using the Unity SDK for anybody that is curious, and I am using the FB.AppRequest to send the invite to the application, the code in my application looks exactly like that in the documentation.

public void InviteFriends() {
        FB.AppRequest(
            message: "Come play this great game!", 
            callback: LogCallback
        );
}

void LogCallback(FBResult result) {
    Debug.Log("Callback was called: " + result.Text);
}

This brings up the box as expected and allows me to invite a friend, and the friend does get the invite, however once they click on the invite they are redirected to a page that looks like this:

Which is causing quite a bit of problems for me; I've checked everything in the application panel and it seems like everything checks out. My google play identifier is correct as-well as my Class Name. My key hashes are all correct. I don't know what else I can do. If you'd like to look up my bundle identifier on the play store it's buzz.qualify and I'm sure that you'll find it with ease.

I should also add that I have an application page which can be found here: https://www.facebook.com/pages/Qualify/1647231425506903?fref=ts

This page is linked to the facebook application in the developer console as-well.

What can I do to resolve this issue? Is it in the code? Please help, this has been a 4 day long set-back and we're losing progress rapidly because of it.

It's been a few days now, we're now paying someone for a fix through paypal.

Answer 1

Do you have Canvas App setup on Facebook for your Android Game?

If not, read Requirements for Invitable Friends.

It states that your game request will...

direct recipients to one of the following places:

1. Your app on Facebook Canvas.
2. Your native app on iOS or Android, if installed.
3. The Apple App Store or Google Play, if not installed.