The #1 thing that can lead to crashes is the graphics driver crashing. Updating it has a good chance of fixing things. Should it still crash, you can remove the file
C:\Users\<username>\AppData\LocalLow\HachiGames\D-Sim\game_settings.json
On the next start of the game, it will start with the settings menu before loading anything else. You can try and try and turn on "Simple Hair", since the strand hair is the most likely to cause issues. Also lower the quality settings depending on your graphics card VRAM.
If you play the game with higher settings than your VRAM size, there will be a lot of stuttering, because system memory and VRAM have to constantly exchange data to draw a single frame. This will cause stuttering, even though the graphics performance would be enough to handle the load. I've seen some complaints because of it, unfortunately. I'll try to implement a VRAM warning, but it's unfortunately not trivial to determine how much an application is actually using (i.e. it's hard to filter out other applications and isolate the game's vram taken)
I've done some things to automatically chose the right settings, but that only works on NVidia cards.