Grouping (number range ) and reference customer MUSTALL do not correspond

Hi experts,

When creating a contract parterner (type Person) t-code FPP1, I use the Reference customer MUSTALL define in customizing.

But the reference customer I have entered in Itendification tab is not created in SD and I face the following error:

"Grouping (number range ) and reference customer MUSTALL do not correspond"

For the contract partner I use internal number range Z1 (From 2100000000-To 2199999999).

I define the following reference customer in IMG:SAP Utilities/Master Data/Business Partner/Settings for creation Standard Customers/

RTcat=MKK

NConv= MUST

EC=checked

MC=checked

Addresswhere-used GR = CON_OBJECT

Ref. Customer = MUSTALL

There is a post on the forum I read but I dont get my issue solved.

Please any idea to solve this ?

Br,

Thierno