500MB scene freezes at frame 79 of 800

I used blender 3.2 (now upgraded to3.4.1) and have a strange error.
Blender freezes at frame 79 when I render (on another machine too).
single frame or animation.
I use cycles. The error appears with CPU or GPU rendering.

How can I find out what is stopping blender in this frame?

thank you

When you say it freezes… do you mean it becomes unresponsive and crashes, or it just slows down? How long have you waited? Some frames take longer to render than others, if it’s not actually crashing I’d give it half an hour or so to see if it renders