Strange behavior proteus vs web client

Support Developer
3

so i narrow down - maybe a mis configuration i’ll open a new subject.

i finally found…
play with proteus i gave a date french format that was inserted french format (so in the future for the tryton databases ???) and the code

says

after_invoices = cls.search([
('sequence', '=', invoice.sequence),
    ['OR',
     ('accounting_date', '>', date),
        [
           ('accounting_date', '=', None),
        ('invoice_date', '>', date),
            ],
               ],
               ], limit=1, order=[('accounting_date', 'DESC')])

so it is not possible to enter an invoice with a date BEFORE one invoice entered. the error message was not helping at all