Hello cychun and thanks for reporting this issue!
From the bugreport.txt it seems like you were removing a material, is that right?
Now, in order for us to be able to fix this problem, we must be able to reproduce it and for that we need to know the exact steps that you took that made C4D crash. If you are able to make C4D crash again in a simple scene, then great! If you can make it crash in your scene and if you can send us your scene through our private uploader, that would be great as well.
Unfortunatelly, I'm not sure we can do much if we are unable to make that crash happen again. But a description of what you were doing will be great in any case!
