Compiles but gives "Error #1034: Type Coercion failed" during test

I am working on a flash based web application. The front end is written in flex: MXML and ActionScript. The project builds fine in FlashDevelop, but when I test that using F5, it throws error.

Line of code:

[Bindable]
public var currentStateDataProvider:ArrayCollection = new ArrayCollection();

Error message:

[Starting debug session with FDB]
[Fault] exception, information=TypeError: Error #1034: Type Coercion failed: cannot convert mx.collections::ArrayCollection@c2acfc9 to Array.

Is there anything wrong the way I am declaring and initializing the variable?