Hi Muneesh,
Thank you for your post!
I was wondering do you also experience this kind of crash in this particular file when the number of rays is low, say 1E6? Also, were you saving ZRD file during ray trace when the crash happened? If you do, the saving ZRD operation may slow down the ray trace and also the ZRD file generated can be very large which might cause crashing.
If this crash persists, could you please run a File Collector so OpticStudio will generate a Diagnostic package and send it in so we can take a look? Please don't include your lens file if it's proprietary. All we need is the system information, highlighted in the red box below. This hopefully can shed some light on what might have caused the crash.

Thank you!
Best regards,
Hui