If the feature is not working, an alternative is to do a batch update via Contacts>Database Management>Manage Contacts>Import Contact via a CSV file with supporter IDs.

  1. Go to Contacts>Database Management>Manage Contacts>Import Contact.
  2. Click New Import Batch
  3. Browse for the file and select "Update based on Kintera Supporter ID"
  4. Click Next, then Next once more
  5. Select the newsletter you wish to have them subscribed to
  6. Finish the import and let it run