I was editing a Micrologue part in the key editor, while the four track project was playing in repeat. Cubasis 3 just disappeared from the screen as I was moving a note. When I restarted the app, it loaded the project with the part missing that I was writing. I can only guess it had not saved it yet.
Project had four MIDI tracks with Microsonic, MiniSampler and 2 x Micrologue. No other plugins were inserted.
Previously on another project, while switching a track’s instrument to Micrologue, the audio engine emitted a noise and the app hung. Had to kill it.