You have created the user in the portal, or imported the user, using the User Management Engine (UME).
There is an assignment between the users in the portal and in the back-end system (for example, ECC system). You can ensure this, for example, by logging on using Single Sign-On or using User Mapping.
Assign the following roles to each portal user:
HR Administrator (com.sap.pct.erp.hradmin.11.HRAdministrator)
ERP Common (com.sap.pct.erp.common.erp_common)