Good evening

I created a calculated field with Odoo Studio on the 'Bill of Materials' model in order to divide the quantity to be produced (base field) by the product density (associated field).

but every time after execution I end up with errors and I don't understand where this problem comes from

Here is the code I am using:

for record in self :

                record.x_studio_cv =   record.product_qty / record.x_studio_density

Thank you in advance for your help