Error performing actions on custom search results (add to group, add to event, more?)

This happens on the demo at http://drupal.demo.civicrm.org/:

1. Open any custom search that supports actions on a collection of selected found contacts (I tried with "Household Name and State" and "Zip Code Range")
2. Submit the search form with criteria that will get some result (I used % in the Household name field)
3. In the results, select any or all of the resulting contacts.
4. Select the action "add Contacts to Group" and click "go" (I also tried this with "Add Contacts to Event", with the same results).
5. On the "Add Contacts to A Group" form, select a group (I used "Administrators" and also tried with a couple of others), then click "Add to group".
6. Observe the fatal error message: "Sorry but we are not able to provide this at the moment. Could not get details for custom search."

BTW, it does appear that the contacts are actually added to the group, despite the fatal error.