Fixed: Value cannot be null Parameter Name: source

I ran into this message whilst coding an app for Xamarin, but this is definitely an odd way to report the error that's actually happening, but as always there's always one error in a project where you think. What the hell is that? Value cannot be null Parameter Name: source usually happens on an IEnumerable for one reason.

Chances are that the List/IEnumerable you're trying to work on is null or an object within the list is null, but I'd check the former first as it's more likely.

That's it. Short post but an annoying error message for such a simple answer.