Custom Search Include/Exclude error message
This error is displayed when you don't have any groups OR tags available on your site.


Check if you see any groups listed in civicrm/group?reset=1.
Similarly, check if you have at least one tag available in civicrm/tag?reset=1.


In your case, I think you don't have any tags created on your site. As a hacky workaround - you can create a dummy tag from Contacts -&gt; New Tag menu in order to get rid of the error on the search screen.