I met this error several time, and it was pretty hard to fix, cause I didn’t know why this error was raised at all.
The reason was this: I used a local var name identical to some namespace name.
Let’s say you have a namespace vk, and you declare a local var vk:Object and then are trying to call some method on it. To as3 compiler vk is not a local var but a namespace, woala)) The solution is just select another name for you local var đŸ˜‰ Cheers!