Query MIM portal for groups with no owner

Hey all, how do I query the MIM portal for groups with no owner? The guidance provided in this thread is not working for me:

https://social.technet.microsoft.com/Forums/en-US/9705ab4c-51b9-42d8-bb52-85816fb479c2/powershell-to-query-groups-having-no-owners-in-fim-portal?forum=ilm2

Specifically, the recommended filter (Filter = /Group[Owner !=/Person])is not working for me and results in an error:

Did something change in the filtering syntax?

Any guidance is appreciated.  Thanks!