Cordova Facebook plugin - cannot show dialog

Question

I'm trying the basic example seen here : Facebook4 plugin

facebookConnectPlugin.showDialog({
    method: "send",
    caption: "Check this out.",
    link: "http://example.com",
    description: "The site I told you about",
    picture: "http://example.com/image.png"
}, function(result) {
    // Success!
    $timeout(function () {
        $ionicLoading.hide();
    });
    console.log("success", result);
}, function(err) {
    // An error occured. Show a message to the user
    $timeout(function () {
        $ionicLoading.hide();
    });
    console.log("error - ", err);
});

And I get this error message :

Cannot show dialog

I'm really not sure what's going on... And looking for a long time now without making any progress. Any help ?

I don't think it's linked but the permissions asked on login are

["public_profile", "email", "user_birthday"]

Thanks !