iOs9 XCODE error: JSON.stringify cannot serialize cyclic structures

I updated my Xcode today and run my Ionic app on iOs9 build. New error pop up on Xcode console each time I click from a ng-repeat list to a detail view. Error is:

error JSON.stringify()ing argument: TypeError: JSON.stringify cannot serialize cyclic structures.

I do not know what is causing this error and it only output this error in Xcode when run the app on my iPhone 5s. I can feel there is a delay each time I click a list item within a ng-repeat list. So I am using AngularFire / Firebase to load the items from firebase and ng-repeat them on an Ionic list. Tag each item in a list go to a detail view. Error output when I tag the item.