That looks like a bug. The workaround should be to change focus to something else before removing a component from the stage.
I'm not actually trying to remove anything from the stage. I get this error just by clicking on another object and changing focus from one thing to another. One thought I had was to just put a try..catch around Line 2466 in UIMovieClip. I downloaded the adobe flex SDK and tried to find that class, but I can't find the file. I found most of the other package folders, but no mx.flash. How do I change it and use that file when I compile?
Should be in the flash-integration project.
Indications are that the widgets are no longer on the stage when they lose focus.
I can't find the flash-integration folder at this location:
C:\Program Files\Adobe\Adobe Flash Builder Beta 2\sdks\3.4.1\frameworks\projects
I also looked in the same place in the sdk files I downloaded. Am I way off? I can still can't find the UIMovieClip file.
We also tried changing the focus, but that was no help. I still can't see how anyting is being removed from the stage. When I get the error, all I do is click on another object thereby switching the focus from one widget to another. It also happens when the flash player itself loses focus. Thanks for your help!
Maybe we don't package that source with the SDK. It might be installed with the FCK. If you can find it in your Flash directories you can probably modify it there.
It might be easier to figure out why stage is null at that point.