I have module to display date selection in the search area of the sales order line view. It works in one database and it doesn't work in another.. Am confused because it's working with one database.

Here is the error:

The xml code:

<openerp> <data>

    <record id="view_sale_orderlinedate" model="ir.ui.view">
        <field name="name">sale.order.line.dateinherit</field>
        <field name="model">sale.order.line</field>
        <field name="type">tree</field>
        <field name="inherit_id" ref="sale.view_order_line_tree"/>
        <field name="arch" type="xml">
            <field name="order_id" position="after">
                        <field name="ordered_date" />
                        </field>
            </field>

    </record>

    <record id="view_sale_orderlinedate2" model="ir.ui.view">
        <field name="name">sale.order.line.dateinherit2</field>
        <field name="model">sale.order.line</field>
        <field name="type">search</field>
        <field name="inherit_id" ref="sale.view_sales_order_line_filter"/>
        <field name="arch" type="xml">



          <field name="salesman_id" position="after">  
                        <field name="due_date_from" filter_domain="[('ordered_date','>=',self)]"/>
                        <field name="due_date_to" filter_domain="[('ordered_date','<=',self)]"/>
          </field>
        </field> 
    </record>

</data>

</openerp>

from osv import fields, osv
class sales_invoice_date(osv.osv):
_name='sale.order.line'
_inherit='sale.order.line'
_columns={
    'ordered_date': fields.related('order_id', 'date_order', type='date', relation='sale.order', select= 1, string='Date Ordered'),
    'due_date_from':fields.function(lambda *a,**k:{}, method=True, type='date',string="Due date from"),
    'due_date_to':fields.function(lambda *a,**k:{}, method=True, type='date',string="Due date to"),

}

sales_invoice_date()