Thank you! i've already tried with this code but the view which is opened by default is the form instead of the tree

Pass your tree view in the return action as follow:

'view_id': self.env.ref('module_name.xml_id_of_tree').id

If i add the line whith the reference i get the errror:

TypeError: this.view_order[0] is undefined

I've tried too with view_id and i get the same error

ok then try with the following. I hope that will work.

tree_view_id = self.env.ref('module_name.xml_id_of_tree').id

form_view_id = self.env.ref('module_name.xml_id_of_form').id

'views': [(tree_view_id, 'tree'), (form_view_id, 'form')],

Thank you very much!! Finally I got it

The code which works is:

@api.multi

def gestionar_adjuntos(self):

self.ensure_one()

empresas = self.env['or.empresas'].search([('vat', '=', self.vat)])

empresa_cli = empresas[0].id

result = {

'name': 'Gestionar archivos adjuntos',

'res_model': 'or.archivos',

'type': 'ir.actions.act_window',

'views': [(False, 'tree'), (False, 'form')],

'domain': [('cliente_id', '=',empresa_cli)],

}

return result