Civi 5.15.1, Wordpress 5.2.3
I'm trying to get a list of all contacts who are not in any group (Smart or otherwise). I've done this two ways, with the same result: the first is by filtering the Constituent Summary report, and the second is using the Search Builder.
In either case, when I set the Group(s) filter to 'Is Empty', I get this message: "Sorry, due to an error, we are unable to fulfill your request at the moment. You may want to contact your administrator or service provider with more details about what action you were performing when this occurred."
And when I set the Group(s) filter to 'Is Null' (available via Search Builder only, not the report), the resulting list includes contacts who are in Smart Groups, whom I want to exclude.
I'd prefer not to use the Import Contacts workaround provided by Nicholai here: How to find contacts with no group?
And @Xavier's extension based on it does not seem to be available anymore (https://civicrm.org/extensions/lonesome-find-contacts-without-group).
Does anyone have any other ideas? Thanks!