I am using a tree view inside a form view
<field name="search_matches" nolabel="1" widget="many2many_list">
<tree version="7.0" editable="bottom">
<field name="chk_bob" on_change="onchange_owner_id(chk_bob)" widget="selection"/>
<field name="user_id"/>
<field name="stock_type"/>
<field name="structure_building"/>
<field name="property_vaastu"/>
<button name="contact" type="object" string="Play" />
</tree>
</field>
it is giving an error message