Field default_provider_id used in domain of <field name="product_id"> ([('partner_id', '=', default_provider_id),('sale_ok', '=', True), '|', ('company_id', '=', False), ('company_id', '=', parent.company_id)]) must be present in view but is missing.
<odoo>
<data>
<record id="trade_party2nd_inspect_order" model="ir.ui.view">
<field name="name">trade_party2nd_inspect_order</field>
<field name="model">sale.order</field>
<field name="inherit_id" ref="sale.view_order_form"/>
<field name="arch" type="xml">
<xpath expr="//field[@name='partner_shipping_id']" position="after">
<field name="provider_id" widget="many2one_tags"/>
</xpath>
<field name="order_line" position="attributes">
<attribute name="context">{'default_provider_id': provider_id}</attribute>
</field>
<field name="product_id" position="attributes">
<attribute name="domain">[('partner_id', '=', default_provider_id),('sale_ok', '=', True), '|', ('company_id', '=', False), ('company_id', '=', parent.company_id)]</attribute>
</field>
</field>
</record>
</data>
</odoo>