Unable to change standard datatypes


May I know why I am unable to change standard doctypes in customize form while I am trying to change the doctype.I am getting an error like " Fieldtype cannot be changed from Check to Data in row 13 " in every standard doctype even I used
“developer_mode”: 1

Hope I am waiting for the answer

Thanks & Regards

This is a standard validation that field order for them cannot be changed by them. Can you please elaborate your requirement? If it’s genuine, we can change that in the main doctype as well. The standard Print Format is generated based on the actual field location, hence it’s preferred to remain in it’s place.