This has now happened to me too. A simple project with 2 midi tracks and 2 audio tracks which had been used with Audiobus. It was only around 24 bars long. I saved it, and when reloaded it took maybe 5 mins to even load and there were an enormous number of tracks and when I scrolled down and tried to delete some tracks, it just froze.
This needs to be fixed urgently (as I think you are aware). Although it saddens me to say so, I no longer trust the stability to be able to use Cubasis on any significant projects until this and the undo bug is fixed.
Just checked and there is no new Cubasis crash log for this!