Hi Sharada,
Sorry for the delayed response.
I was able to reproduce the mentioned issue.
To avoid the crash do the following :
1) Change the ChartSeriesType from scatter to spline.
2) Avoid the code which reduces the spline tension.
Please have a look at the attached sample which helps you to print the Zoomed chart without any crash.
Thank you for your continued interest in Syncfusion products.
Regards,
Jaya
DragGraph2.zip