What the cause and how to fix this error :

"Canot be located in parent view"

[Update]

This is the code, I can't add new tab after Accounting :

<?xml version="1.0" encoding="utf-8"?>
<openerp>
<data>

<record model="ir.ui.view" id="product_form_view">
    <field name="name">product</field>
    <field name="model">product.product</field>
    <field name="type">form</field>
    <field name="inherit_id" ref="product.product_normal_form_view"/>
    <field name="arch" type="xml">
    
        <xpath expr="//page[@string='Accounting']" position="after">
            <page string="KPB" col="1">
                <group col="4">
                    <field name="color"/>
                </group>
            </page>
        </xpath>
        
    </field>
</record>

</data>
</openerp>