Flash CS6 duplicating layers in movie clips at every save

Question

In all of the movie clips in this FLA I start out with

Every time I save and regenerate the SWF I end up with a set of duplicate layers added and additional frames but only on the actions layer?!:

Has anyone run into this before? It's driving me crazy.

Answer 1

This appears to have occurred after multiple attempts to import an Adobe Illustrator file. The library then contained imported folders which seem to have recursively referenced themselves causing the FLA to become useless but not corrupted as it would open and render.