There can be few reasons for that. First is the third party plugins. That may happen for example with the older version of AOM Invisible Limiter. Cubase always crash after closing the project, save-close Cubase procedure or sometimes even replacing the plugin with something else. It is caused by the faulty programming of the plugin not Cubase.
Another reason might be due to slow hard drives. Since I moved from my old Mac Pro tower to mode powerful MacBook Pro but with external drives I sometimes have issues with slow transfer between them and the computer. That causes freezing or very seldom crashing when Cubase is loading large waveforms or libraries from the external drive. I finally must upgrade from conventional to external SSD Thunderbolt drive.
The last thing might be related to your system. Since I’m on Mac not Windows, I can not help you with that. I will not tell you to switch systems but even my 10 years old MacPro is working flawlessly today with the latest plugins and software.
I hope that will help