We have an WPF/MVVM application that uses SharePoint 2010 Search QueryService. We are in the process of upgrading SharePoint 2010 to 2013. I enabled FQL in SharePoint 2013 server by adding a new default Search ResultSource with Query Transformation string setup as “{?andnot({searchTerms},filter(contentclass:"urn:content-class:SPSPeople*"))}”. This one enables FQL for SharePoint 2013 by looking at article http://msdn.microsoft.com/en-us/library/jj163973.aspx.
But our FQL search still return 0 results without any exceptions from Client Object Model. I checked that we didn't use any deprecated operators under FQL CAML queries. This web site http://www.onlysharepoint2013.com/2013/01/fast-query-language-fql-features-that.html lists all the deprecated operators for SharePoint 2013 FQL.
I tested the same FQL CAML query using SPCAMLQueryHelper.exe and it does return correct rows.
What could cause FQL CAML queries still not working on SharePoint 2013?
Thanks a lot.