Hi.

This is a very strange behaviour. Let me explain.

I need to add a fied to invoice form. To do that

1) I've created custom module to inherit account.invoice and added the field

2) I've created a view and inherited account.form_view

3) I've inserted the new field in the new view.

Stange behaviour:

If I put the field in the main body (not into a notebook element) of th invoice, all works fine. If I insert the field after invoice's secodary field (in my case this secondary field is "name" inside "Other info" notebook), a "field does not exist" error arises.

My model:

class InvoiceInherit (models.Model):
    _inherit = 'account.invoice'
 ref2 = fields.Char(string='Reference2',readonly=True, states={'draft': [('readonly', False)]}, copy=False, help='It will appear in invoice doc under "Client order''s date')

My view ("invoice_form_ref2"):

<?xml version="1.0" encoding="UTF-8"?>
<odoo>

    <record id="view_partner_form_id" model="ir.ui.view">
        <field name="model">res.partner</field>
        <field name="inherit_id" ref="base.view_partner_form"/>
        <field name="arch" type="xml">
            <field name="ref" position="after">
                <field name="provider_id"
                       placeholder="Provider ID"/>
            </field>
        </field>
    </record>

    <record id="invoice_form_ref2" model="ir.ui.view">
        <field name="model">account.invoice</field>
        <field name="inherit_id" ref="account.invoice_form"/>
        <field name="arch" type="xml">
            <field name="name" position="after"> <-- with this, raise an "field ref2 does not exist" error on update module
                <field name="ref2"/>
            </field>
        </field>
    </record>
</odoo>

if I use

<field name="payment_term_id" position="after">

All things work fine.

Please, note that both fields "name" and "payment_term_id" exists into account.invoce but are rendered in different positions:

"payment_term_id" is redered in the "main" invoice body, but

"name" is rendered inside "other info" notebook.

Thank yu for your help