Hi,

1.Check whether the external id gives properly.From the for view click on the debugger and click edit form view you will get a window and copy the external id into inherit id.

<record ………………………………………

  <field name="inherit_id" ref="external_id"/>

    <field name="arch" type="xml">

        <xpath expr=”.....................................

        </xpath>

    </field>

  </field>

</record>

For adding an extra field

This field should be present in the model(python file)

<record id=....................................................................

    <field name="arch" type="xml">

        <xpath expr="//field[@name='manager_id']" position="after">

            <field name="registration_Date"/>

        </xpath>

    </field>

</record>

For disabling a field

<record id=.......................................................................

    <field name="inherit_id" ref="external_id"/>

        <xpath expr="//field[@name='first_contract_date'] position="attributes">

            <attribute name="invisible">True</attribute/>

        </xpath>

    </field>

</record>

3.Gives the module name in the manifest inside ‘depends’ which is to be inherited.

‘depends’ : [‘fleet’],

Regards

Check the Parent xml View, model, and inherit_id.

Then you have to match exact tag for xpath according to base view. 

For example, to inherit and modify any view form calendar, 

<record id="crm_calendar_inherit_view" model="ir.ui.view">
    <field name="name">CRM Leads Inherit Calendarfield>
    <field name="model">calendar.eventfield>
    <field name="inherit_id" ref="calendar.view_calendar_event_calendar"/>
    <field name="arch" type="xml">
        <xpath expr="//field[@name='partner_id']" position="after">
            <field name="opportunity_id"/>
        xpath>
    field>record>