We are using NW 7 Portal for ESS.
Authentication on Portal is via LDAP.
SSO is via User ID and password since backend ECC and LDAP users are different.
When trying to map a certain user in the Portal User Admin screen I get the following error:
An unexpected error occurred when retrieving all backend systems available for user mapping.
Under "User mapping for system access":
There are no systems available for user mapping for the selected principal.
This only happened for 1 user so far. Others are successfully mapped and can view the necessary ESS screens and correctly get info from the backend.
I have checked that the system object has a alias and that its permissions is set to allow Everyone Read + end user access.
UME configuration has a reference system defined.