MDM Import map Error

Hi Experts,

I have a requirement where I have to update the MDM import map to accomodate additional fields as some new fields have to be imported in MDM in future.

I have created these fields in MDM; PI has completed the required mappings for these additional fields. I have updated the new XML schema in Admin tables-XML schemas, and updated ports table.

Now when I am trying to open the import map using the new XML file I am getting the error “unable to retrieve unique value for fields XXX’.

I am getting this error with the old XML files also .

Please suggest what can be done to avoid this error and update the import map(by mapping the new fields) to enable automatic import

Thanks in Advance!