InfoPath Dev

I ran into this problem and it turned out to be that I was loading GetUserCollectionFromGroup web service on form load. I was passing a sample value group in the Data Connections. I gave everyone visibility to the group I had as the sample and the error went away. Strangely enough, this was only happening to one person out of 5000+ users.

It's odd that you were able to query the Person or Group field from a SharePoint list within InfoPath 2010/2013. Maybe I'm missing something. When I try to set a query fields value all of the fields show up except Person and Group fields.  Is there something extra I need to do to set a fields value and it query the ...