Why Elvis (?.) operator doesn't work with async-await?
The way await is translated is that first, GetAwaiter() is called on the awaited object (in your case, a Task). It then does some other complicated things, but those are not relevant here:
await MyClass?.Job();Compiles to:
var awaiter = MyClass?.Job().GetAwaiter();// more codeSince Task.GetAwaiter() is an instance method and you're calling it with a null Task, you get a NullReferenceException.
As a curiosity, it is possible to await a null awaitable, as long as its GetAwaiter() is an extension method that accepts null:
public class NullAwaitable { }public static class Extensions{ public static TaskAwaiter GetAwaiter(this NullAwaitable _) => Task.CompletedTask.GetAwaiter();}public class MethodClass{ public NullAwaitable Job() => new NullAwaitable();}MethodClass MyClass = null;await MyClass?.Job(); // works fine