correccion

views/fields_view.xml

@@ -14,7 +14,7 @@
                     <attribute name="attrs">{'invisible':True}</attribute>
                 </field>
                 <field name="partner_id" position="replace">
-                    <field name="partner_id" on_change="on_change_partner_id(partner_id, name)" domain="[('customer','=',True)]"/>
+                    <field name="partner_id" on_change="on_change_partner_id(partner_id, name)" domain="[('customer','=',True)]" required="1"/>
                 </field>
                 <field name="manager_id" position="replace">
                     <field name="manager_id" context="{'default_groups_ref': ['base.group_user', 'base.group_partner_manager', 'account.group_account_manager']}" string="Responsable"/>