Note that Crowd Partners can be created in SAP ECC/S4 as both vendors, and Business Partners. Learn more: /PACG/ECM_VENKG - Allowed Vendor account group
It is necessary for allowed vendor account groups to be customized in transaction /PACG/ECM_VENKG. Business Partner crowd class and crowd character should be set as shown below.
Group - vendor account group
CreatDef - Default Vendor account group in creation mode/inbound