-[_SwiftValue encodeWithCoder:]: unrecognized selector sent to instance

You can also use this approach using Enum rawValue. It might help you to archivedData and unarchiveObject a complete model object.

Color Enum With Hex value:

enum PlayerColor: String {
    case red = "#FF0000"
    case silver = "#C0C0C0"
    case gray = "#808080"
    case black = "#000000"

    var description: String {
        return self.rawValue
    }
}

 import Foundation

class Player: NSObject, NSCoding {

    private var name: String!
    private var score: Int!
    private var color: PlayerColor!

    init(playerName: String, playerScore: Int, playerColor: PlayerColor) {

        name = playerName
        score = playerScore
        color = playerColor
    }

    required convenience init(coder aDecoder: NSCoder) {
        let name = aDecoder.decodeObject(forKey: "name") as! String
        let score = aDecoder.decodeObject(forKey: "score") as! Int

        if let value = aDecoder.decodeObject(forKey: "color") as? String{
            color = PlayerColor(rawValue: value)
        }
        self.init(playerName: name, playerScore: score, playerColor: color)
    }

    func encode(with aCoder: NSCoder){

        aCoder.encode(name, forKey: "name")
        aCoder.encode(score, forKey: "score")

        let value = color!.description
        aCoder.encode(value, forKey: "color")
    }

}

Here's the solution I implemented:

Player.swift:

import Foundation

    class Player: NSObject, NSCoding {

        private var name: String!
        private var score: Int!
        private var color: String!

        var playerName: String {
            get {
                return name
            }
            set {
                name = newValue
            }
        }

        var playerScore: Int {
            get {
                return score
            }
            set {
                score = newValue
            }
        }

        var playerColor: String {
            get {
                return color
            }
            set {
                color = newValue
            }
        }

        init(playerName: String, playerScore: Int, playerColor: String) {

            name = playerName
            score = playerScore
            color = playerColor
        }

        required convenience init(coder aDecoder: NSCoder) {
            let name = aDecoder.decodeObject(forKey: "name") as! String
            let score = aDecoder.decodeObject(forKey: "score") as! Int
            let color = aDecoder.decodeObject(forKey: "color") as! String
            self.init(playerName: name, playerScore: score, playerColor: color)
        }

        func encode(with aCoder: NSCoder){
            aCoder.encode(name, forKey: "name")
            aCoder.encode(score, forKey: "score")
            aCoder.encode(color, forKey: "color")
        }

    }

PlayerStore.swift:

func savePlayers(){
    let encodedData = NSKeyedArchiver.archivedData(withRootObject: _playerArray)
    defaults.set(encodedData, forKey: playerKeyForDefaults)
}

func loadPlayers(){
    if let decoded = defaults.object(forKey: playerKeyForDefaults) as? NSData {
        let array = NSKeyedUnarchiver.unarchiveObject(with: decoded as Data) as! [Player]
        _playerArray = array
    }

}