Webshop users in ECC

Hi

We want to have the users (end users) to be maintained in ECC instead of having them in CRM.

We configured the backend and we could create the users also in ECC.

But when we try logging in with the users with ECC backend, we get the following error:

"ISA Framework: com.sap.isa.core.PanicException: R3 Lean Order Interface is not active"

Any help?

Regards,