CMCIC payment method error

-- HikaShop version -- : 2.6.4

Hi,

We have asked our bank to have access to the old payment system and not to the new one called monetico.
Once we place an order and go to the test platform, the payment process goes fine until the end where we get an error (see attached screenshot):
CGI2 : NOT OK and all our orders are canceled, payment not valid...But our bank say that the payment has been accepted, just the "acccusé de réception" is not valid form the bank I get this "REQUETE EMISE PAR NOTRE SERVEUR : http://:80?"

Can you please tell what's wrong ?

PS you forum say that our Hikashop version is not up to date as our site says that we have the latest stable version...? What's true ?

Thanks in advance for your help and advise,
Best Regards
Stéphane