File "/opt/odoo/odoo-10.0/odoo/models.py", line 1083, in _validate_fields
    raise ValidationError("%s\n\n%s" % (_("Error while validating constraint"), tools.ustr(e)))
ParseError: "Error while validating constraint

Field `session_ids` does not exist

Error context:
View `partner.instructor`
[view_id: 560, xml_id: n/a, model: res.partner, parent_id: 124]
None" while parsing /opt/odoo/odoo-10.0/addons/Open Academy folder/views/partner.xml:5, near
<record model="ir.ui.view" id="partner_instructor_form_view">
            <field name="name">partner.instructor</field>
            <field name="model">res.partner</field>
            <field name="inherit_id" ref="base.view_partner_form"/>
            <field name="arch" type="xml">
                <notebook position="inside">
                    <page string="Sessions">
                        <group>
                            <field name="instructor"/>
                            <field name="session_ids"/>
                        </group>
                    </page>
                </notebook>
            </field>
        </record>