hello,

i have this view 

<record id="view_cave_emb_entree_tree" model="ir.ui.view">
    <field name="name">Entree Emballage</field>
    <field name="model">cave.emb.entree</field>
    <field name="arch" type="xml">
    <tree string="Entree Emballage">
        <field name="name"/>
        <field name="client"/>
        <field name="total_entree"/>
        <field name="emballage"/>
        <field name="total_reste"/>
    </tree>
    </field>
</record>
<record id="view_cave_journee_search" model="ir.ui.view">
    <field name="name">Entree Emballage</field>
    <field name="model">cave.emb.entree</field> 
    <field name="arch" type="xml">
        <search string="Entree Emballage">
            <field name="name"/>
            <field name="emballage"/>
        </search>
    </field>
</record>
<record id="action_emb_entree" model="ir.actions.act_window">
    <field name="name">Entree Emballage</field>
    <field name="type">ir.actions.act_window</field>
    <field name="res_model">cave.emb.entree</field>
    <field name="view_type">form</field>
    <field name="context">{'group_by':['client', 'emballage']}</field>
    <field name="view_mode">tree,form</field>

    <field name="view_id" ref="view_cave_emb_entree_tree"/>
    <field name="help" type="html">
    <p class="oe_view_nocontent_create">
            Cliquer ici pour une entree de caisse
    </p>
    </field>
</record>

i want to group tree by client and emballage but i got this error:

File "C:\Program Files\Odoo 11.0e\server\odoo\osv\expression.py", line 846, in parse
    raise ValueError("Invalid field %r in leaf %r" % (left, str(leaf)))
ValueError: Invalid field 'active' in leaf "<osv.ExtendedLeaf: ('active', '=', True) on cave_emb_entree (ctx: )>"

how can i correct