A general purpose configuration file boilerplate

ApplicationConfig.cs

using System;
using UnityEngine;
using System.Collections;
using System.IO;
using System.Runtime.Serialization;
using System.Xml.Serialization;

[Serializable]
public class ApplicationConfig
{
    private const string FileName = "ApplicationConfig.xml";

    // Configuration properties go here

    private static ApplicationConfig _instance;

    public static ApplicationConfig Instance
    {
        get
        {
            if (_instance == null)
            {
                _instance = LoadFromFile();

                if (_instance == null)
                {
                    LoadDefaultsAndSave();
                }
                return _instance;
            }

            return _instance;
        }
    }

    private static void LoadDefaultsAndSave()
    {
        _instance = new ApplicationConfig()
        {
            // Loading default values go here
        };

        _instance.Save();
    }

    public bool Save()
    {
        XmlSerializer serializer = new XmlSerializer(typeof(ApplicationConfig));

        try
        {
            using (var fs = System.IO.File.Open(FileName, FileMode.Create, FileAccess.Write))
            {
                serializer.Serialize(fs, this);
                return true;
            }
        }
        catch (Exception ex)
        {

            Debug.LogError("Could not Save applicationconfig " + ex);
            return false;
        }
    }

    private static ApplicationConfig LoadFromFile()
    {
        if (!File.Exists(FileName))
        {
            return null;
        }

        XmlSerializer serializer = new XmlSerializer(typeof(ApplicationConfig));

        try
        {
            using (var fs = System.IO.File.Open(FileName, FileMode.Open, FileAccess.Read))
            {
                return serializer.Deserialize(fs) as ApplicationConfig;
            }
        }
        catch (Exception ex)
        {

            Debug.LogError("Could not Load applicationconfig " + ex);
            return null;
        }
    }
}