It sounds like one of your object catagories is corrupted. This has happened to me a dozen times: one of the objects in a catagory gets corrupted (for whatever reason...I don't know why this happens) and then that entire catagory is rendered useless. Whenever you try to import a model into a Bryce scene, is Bryce freezing up? Or does Bryce freeze up when you open a scene file? If your problem is the models, then you'll have to delete that object catagory (not the models) and start another one. A good rule of thumb is not to add too many objects to your catagories, because eventually one will become corrupted. Hope that helps! Doug