I'm working in Commerce Kickstart environment. After checking "Use custom line item type" en product type edit, I have this error.

Notice: Undefined index: type in commerce_backoffice_product_variation_type_form_submit() (line 165 of my-site\profiles\commerce_kickstart\modules\contrib\commerce_backoffice\includes\commerce_backoffice_product.product_variation_types.inc).

And the line item field isn't added