Update All Object Properties on a Single Property Change C#

That's exactly how I thought it should work however, how do I initialize AnotherProperty to a value. I have a windows form which opens when I construct the object and when I implement as you showed me it says that AnotherProperty is null and throws an exception. I'm going to try and show some code snippets of what I have so that hopefully you can tell me where I am going wrong.

        // Interface Base Ability Scores
        public int[] BaseAbilityScore
        {
            get { return baseAbilityScore; }
            set 
            { 
                baseAbilityScore = value;
                UpdateCreature();
            }
        }
        // Interface Adjusted Ability Scores
        public int[] AbilityScore { get; set; }
        // Interface Ability Modifiers
        public int[] AbilityModifier { get; set;

        private void UpdateCreature()
        {
            int score = 0;

            // Update Ability Scores and Modifiers
            for (int idx = 0; idx < AbilityScore.Length; idx++)
            {
                AbilityScore[idx] = BaseAbilityScore[idx] + RacialAdjustment[idx];

                score = AbilityScore[idx] / 2;
                if (score < 0)
                { score = 0; }
                AbilityModifier[idx] = (score - 5);
            }

}

The following is where it throws an exception

        public void UpdatePlayerCharacterSheet()
        {
            // Update Player Character
            //playerCharacter.UpdateCreature();

            // Display Vitals
            nameLabel.Text = playerCharacter.Name;
            raceLabel.Text = playerCharacter.Race;

            // Display Ability Scores
            strengthScoreLabel.Text = playerCharacter.AbilityScore[(int)Ability.Strength].ToString();
            dexterityScoreLabel.Text = playerCharacter.AbilityScore[(int)Ability.Dexterity].ToString();
            constitutionScoreLabel.Text = playerCharacter.AbilityScore[(int)Ability.Constitution].ToString();
            intelligenceScoreLabel.Text = playerCharacter.AbilityScore[(int)Ability.Intelligence].ToString();
            wisdomScoreLabel.Text = playerCharacter.AbilityScore[(int)Ability.Wisdom].ToString();
            charismaScoreLabel.Text = playerCharacter.AbilityScore[(int)Ability.Charisma].ToString();

            // Display Ability Modifiers
            strengthModifierLabel.Text = playerCharacter.AbilityModifier[(int)Ability.Strength].ToString();
            dexterityModifierLabel.Text = playerCharacter.AbilityModifier[(int)Ability.Dexterity].ToString();
            constitutionModifierLabel.Text = playerCharacter.AbilityModifier[(int)Ability.Constitution].ToString();
            intelligenceModifierLabel.Text = playerCharacter.AbilityModifier[(int)Ability.Intelligence].ToString();
            wisdomModifierLabel.Text = playerCharacter.AbilityModifier[(int)Ability.Wisdom].ToString();
            charismaModifierLabel.Text = playerCharacter.AbilityModifier[(int)Ability.Charisma].ToString();
}