Migration discount on customer specific discount product category ends in validity error

Hi,

I am testing discount list migrations.

Aim is to set up discounts per individual customer and product categories.

Manually all works perfectly.

When using the migration templates, as there will be quite some data records that need to be maintained all goes well with no errors in the different steps until the final steps.

I get a error message that IIA1S_Foundation029 Price lists can only be created with combinations that identify the area of validity correctly.

I checked and double checked

1. The validity period in the template and it is valid.

2. Project Sope: pricing opttion: Sales Price and Discount Lists has been activated

3. Scoping questions have been answered: Do you maintain customer discounts on a product category level

4. The "Migration of Discount List" in Integrate and Extend have been included in the scope

Does anybody experienced the same issue? How can it be solved?

Many thanks in advance.

MJ