I have opened one of my cubase 11pro project into cubase 12pro. 12 will no play it without issues. sounds dreadful. It is more than one project. 12 also seems to get my Mac laptop working hard…fan kicks on every time I open it. I’ve never had these issues with C11.
2.6 GHz 6-Core Intel Core i7
16 GB 2667 MHz DDR4