Could you post the code that generates this error?
It would be easier to say why you are getting the error.
Did anyone find a solution to this? It started showing up in my FB 4.5.1 project all of a sudden. Must have turned someone on (or off) by mistake. Very annoying! ;-)
Now it's showing warnings on navigator, stage, addElement, and data. I know I've got to be missing something but I don't know what I've done. Any suggestions are more than appreciated!