I have a big ressource XFL file which keeps a lot of graphic ressources for a computer game.
It contains a lot of externally linked graphic symbols (Linked as AS3 classes)
This file is extremely prone to getting corrupt after just a few changes. It's like walking through a mine-field.
The main symptom is: Suddendly flash starts duplicating layers and Symbols - seemingly endless!
What can it be that triggers this? I always close and re-open the file when this happen and everything is back to normal for some minor changes until it happens again.
There are also some symbols where it takes almost half a minute before it can be displayed in the library preview window when clicking on it in the library, with very high CPU consumptions.
Being a programmer myself I suspect that there is something like a "feedback loop" that causes this behaviour: Some internal back-referencing of nested symbols which gets caught in some kind of loop at a certain point.