Question

I am trying to make the following graph call using the Facebook iOS SDK:

me/mutualfriends/<friend_id>

Using the call:

NSString* mutualFriendsCall = [NSString stringWithFormat:@"me/mutualfriends/%@", friend_id];
[[delegate facebook] requestWithGraphPath: mutualFriendsCall andDelegate:self];

This works sometimes but often (quite often) returns the following error:

Error message: An unknown error occurred

Other calls such as me/friends work almost a 100% of the time.

What might be causing this difference?

Update:
This also is reproducable if you just call the graph api directly, so it is probably not specific to iOS.
https://graph.facebook.com/me/mutualfriends/

Answer 1

This appeared to be a facebook bug which has since been fixed.