C# compilation error on a function returning complex sequence

[sorawee]

I apologize for this complex code, but this is the most I can minimize without losing the bug.

method Main () 
{
  var x1 := 1;
  var x2 := 1;
  var x3 := 1;
  var x4 := 1;
  var x5 := 1;
  var x6 := 1;
  var x7 := [1];
  var x8 := [1];
  var x9 := [1];
  var x10 := [1];
  var x11 := [1];
  var x12 := [[1]];
  var x13 := [[1]];
  var x14 := [[1]];
  var x15 := [[1]];
  var x16 := [[1]];
  var x17 := [[[1]]];
  var _ := () => [[[[x1, x2, x3], []], x12, x13, x14], [[x7, x8, x9], [[x4, x5, x6], x10, x11], x15, x16], x17];
}

It compiles fine to Java, Go, and JS, but errors on C# with the following error message:

Errors compiling program:
(1812,35): error CS0305: Using the generic type 'Func<TResult>' requires 1 type arguments