On a IOS 9.3.5 all of these functions runs fine.
With XCode IOS 10 Simulator these functions are now shutting down the app.
No idea if this is true on REAL DEVICE or only with the simulator.
It looks OK concerning contacts cards.
What about the "groups" ? i read "Groups are currently not implemented" in the february posts.
Any suggestion ? i can live with C/C++/ObjectiveC but i'm lost in the Apple decorative docs.
Your iContactsUtils sample allow me to validate that my XCODE IOS 10 simulator have a bug with CNContactStore... so THANKS A LOT you save hours !
(it runs well with the 9.3 Simulator as well with my phone)