DIBS module Error: This merchant has not configured the correct session settings

zen-cart-v150-full-release
The site is new and have not been updated for a week or so.
I installed it with Filezilla, and everything works (almost)
I'm using DIBS payment solution

I've look in the FAQs but I cant find any solutuion to this specific problem.

My Shop works great with ZenCart. I can sign up and if I order things I get all information needed and so on.
The problem with my shop is that I can't buy really buy anything. When I'm at step 2 of 3 in the Chekout part, and trying click "Continue Checkout" I get this error message:

The DIBS solution I installed on the site is "DIBS_ZenCart-1.3.9-06"
Can this maybe be the problem?

I've configured this when logged in at my Zen cart (Payment Modules)

DIBS Payment Services (Credit Card) dibs (Green dot(/Default)

This is my settings when I edit:

Merchant ID: ********
Enable Test Mode: Yes
Enable Callback: Yes
DIBS Callback session configuration: No
Skip last page? Yes
Calcfee: No
FlexWinLanguage: Auto
Are you sending unique Order ID to Payment Gateway?: No
Capture now: No
PayByBill - Create invoice now: No
PayByBill - Distribution type: No
FlexWin Color: Blue
Pay Type: VISA,MC,AMEX
Logo(s): VISA,MC,AMEX
Are you using 3-D Secure? No
Logo Size: Med
Payment Zone: --none--
Sort order of display: o
Set Order Status: default
MD5K1: *****....
MD5K2: *****....

I appreciate all help and suggestions helping me to fix this error.
This is the first time I've tried to build a E-shop.
Thank you :smile: