i am receiving this error while creating an invoice on a button click 

psycopg2.ProgrammingError: can't adapt type 'file 

Here's my python code 

def create_invoice(self):
    file = self.env['file'].browse(self._context['active_id'])
for rec in self.invoice_line:
    if not rec.is_fully_paid:
        number_of_time = rec.no_of_installment
        per_installment = rec.per_installment
        for line in file.installment_plan_ids:
            if number_of_time and line.installment_number == 1:
                line.update({'amount': line.amount + per_installment})
                number_of_time = number_of_time - 1

if 0 in self.invoice_line.mapped('total'):
    raise ValidationError(_("Unit price of the products should be non zero number"))

prod = [(0, 0, {
    'product_id': rec.product_id.id,
    'name': rec.product_id.name,
    'account_id': rec.product_id.property_account_income_id.id,
    'price_unit': rec.initial_payment
}) for rec in self.invoice_line if rec.initial_payment]

has_initial = True if prod else False

if has_initial:

    invoice = self.env['account.move'].create({
        'file_ids': file.id,
        # 'name': self.name,
        'partner_id': self.membership_id.id,
        'property_invoice_type': 'others',
        'type': 'out_invoice',
        'user_id': self.env['file'].browse(self._context['active_id']).user_id.id,
        'invoice_date': self.date,
        # 'invoice_date_due': self.date,
        # 'account_id': self.membership_id.property_account_receivable_id.id,
        'invoice_line_ids': prod
    })

    invoice.action_post()
    for rec in file.installment_plan_ids:
        if rec.installment_number == 0 and rec.invoice_created != True:
            rec.write({
                'invoice_created': True,
                'invoice_id': invoice.id,
            })


it doesn't pass this line 'invoice_line_ids': prod in debug mode.
Any idea why this error is coming?