Why Resources.LoadAll is not compatible with Flash

In my script I have t$$anonymous$$s code:

 tileSprites = Resources.LoadAll<Sprite>("tiles");

When I build for Flash I get t$$anonymous$$s error: "error CS0308: The non-generic method `UnityEngine.Resources.LoadAll(string)' cannot be used with the type arguments."

It builds fine for every other platform except flash.

Why is Flash throwing t$$anonymous$$s error? and if t$$anonymous$$s can't be fixed what is the alternatives?