I'm using Flash CS4 for Windows XP SP3.
I have a large project (12MB) that was originally created in CS2 (it's an Actionscript 2.0 project) that I have now opened and saved from CS4 (still using Actionscript 2.0). There are many movie clips that use 9-slice scaling in the library. While editing a clip that has a child clip that has 9-slice turned on, that child clip is invisible on the stage. The object is still there, and when I double-click the child clip to edit it, I am able to view the clip correctly, but when I return to the parent movie clip, the child clip is invisible again. When I publish the movie, the child clip appears correctly. When I turn off the 9-slice checkbox, the child appears correctly in the parent again.
Any project that I open or create after having this large file open exhibits the same behavior, even if I close the large file. I have to restart Flash to make the behavior go away. If I have a file open before opening the large file, that file is not affected and works correctly.
Also, a clip that has nested child clips, one of which is a 9-sliced clip, will be be completely invisible in the parent clip, even if some of the other child clips do not have 9-slice checked. For example:
ParentClip1 --> ChildButton1
ChildButton2 --> LabelClip1
ParentClip1 has two children. ChildButton2 is one of those children. ChildButton2 has two of its own children, LabelClip1 and BackgroundClip1. If BackgroundClip1 is set to use 9-slice (it has rounded corners), then neither ChildButton1 or ChildButton2 or its children are visible in ParentClip1 (again, when the file is published everything appears fine in the SWF; this happens only in the Flash CS4 IDE).
Finally, I can select "Edit in Place" to edit nested elements, but "Edit in Place" is greyed out when I have a 9-sliced clip selected. I can only select "Edit Selected" if I want to edit that, and when I do that I jump out of edit in place mode (though I can still navigate back to the parents using the breadcrumbs).
Sorry this is so long. Seems like it's a memory/file size issue. I'd appreciate any advice.
I also have encountered the same issue as you. A flash 8 file has been converted to CS4, and in some of the clips there are some that are 9-sliced.
For some reason having a 9-sliced clip in these assets causes them to become invisible on the Stage at design-time.
I have the latest CS4 update and cannot understand why this would be happening - does anyone have any ideas?
thanks for getting me started on debugging why it was happening as I was at a loss before I saw your post.