ERROR:tryton.common.common:  File "/home/ivan/workspace/tryton26/env/lib/python2.7/site-packages/tryton/gui/window/view_form/view/list.py", line 732, in __sig_switch
    if not self.screen.row_activate() and self.children_field:

  File "/home/ivan/workspace/tryton26/env/lib/python2.7/site-packages/tryton/gui/window/view_form/screen/screen.py", line 306, in default_row_activate
    }, context=self.context.copy(), warning=False)

  File "/home/ivan/workspace/tryton26/env/lib/python2.7/site-packages/tryton/action/main.py", line 172, in exec_keyword
    Action._exec_action(action, data, context=context)

  File "/home/ivan/workspace/tryton26/env/lib/python2.7/site-packages/tryton/action/main.py", line 134, in _exec_action
    icon=(action.get('icon.rec_name') or ''))

  File "/home/ivan/workspace/tryton26/env/lib/python2.7/site-packages/tryton/gui/window/window.py", line 34, in create
    search_value=search_value)

  File "/home/ivan/workspace/tryton26/env/lib/python2.7/site-packages/tryton/gui/window/form.py", line 115, in __init__
    readonly=bool(auto_refresh), search_value=search_value)

  File "/home/ivan/workspace/tryton26/env/lib/python2.7/site-packages/tryton/gui/window/view_form/screen/screen.py", line 93, in __init__
    self.display()

  File "/home/ivan/workspace/tryton26/env/lib/python2.7/site-packages/tryton/gui/window/view_form/screen/screen.py", line 692, in display
    in ('tree', 'graph', 'calendar'))

  File "/home/ivan/workspace/tryton26/env/lib/python2.7/site-packages/tryton/gui/window/view_form/screen/screen.py", line 126, in search_active
    fields = odict((name, fields[name]) for name in  xml_fields)

  File "/usr/lib/python2.7/collections.py", line 51, in __init__
    self.__update(*args, **kwds)

  File "/home/ivan/workspace/tryton26/env/lib/python2.7/_abcoll.py", line 499, in update
    for key, value in other:

  File "/home/ivan/workspace/tryton26/env/lib/python2.7/site-packages/tryton/gui/window/view_form/screen/screen.py", line 126, in <genexpr>
    fields = odict((name, fields[name]) for name in  xml_fields)


From the people.xml
        <record model="ir.ui.view" id="auroville_residents_tree">
            <field name="model">auroville.people</field>
            <field name="type">tree</field>
            <field name="arch" type="xml">
                <![CDATA[
                <tree string="people">
                  <field name="masterlistid" width="100"/>
                    <field name="aurovillename" expand="1"/>
                    <field name="name" expand="1"/>
                    <field name="surname" expand="1"/>
                    <field name="telephone" expand="1"/>
                    <field name="email" expand="1"/>
                    <field name="contactperson" expand="1"/>
                </tree>
                ]]>
            </field>
        </record>