Help delete single contact in Marshmallow

[Android Question]

I have one lousy contact I want to delete. The phone is a ZTE Sonata 3 with Marshmallow 6.0.1. It says "You have deleted a required permission". What is it and how do I get it back? I just want to get rid of this one jerk's phone number.

 

[Hadron]

I don't have Marshmallow, so am only guessing here, but did you at any point deny a permission to the contacts app (such as the ability to write to storage)? If you go into Settings > Apps > All and find the phone or contacts apps (or whatever else you are using) and look at its permissions are there options to manage them there? If so, turn on any that are off.

 

[AZgl1500]

on my Samsung GS5, in Settings, there is a sub menu "Permissions"