C # byte array for image not working with identical byte arrays

Complete code

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        //Display byte array as image
        private void button1_Click(object sender, EventArgs e)
        {
            pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
            Image img = ByteArrayToImage(File.ReadAllBytes("")); //fill with path info

            pictureBox1.Image = (Image)img.Clone();
        }

        //Convert to image from bytes
        public Image ByteArrayToImage(byte[] byteArrayIn)
        {
            using (MemoryStream ms = new MemoryStream(byteArrayIn))
            {
                ms.Position = 0;
                Image returnImage = Image.FromStream(ms);
                return returnImage;
            }
        }

        //Open Image for conversion
        private void loadImage_Click(object sender, EventArgs e)
        {
            OpenFileDialog opf = new OpenFileDialog();
            DialogResult dr = new DialogResult();
            dr = opf.ShowDialog();
            if (dr == DialogResult.OK)
            {
                pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
                pictureBox1.Image = Image.FromFile(opf.FileName);
            }
        }

        private void convertImage_Click(object sender, EventArgs e)
        {
            //Choose Path to Save To
            SaveFileDialog saveDialog = new SaveFileDialog();
            saveDialog.Title = "Choose Directory and File Name";
            saveDialog.Filter = "Canga Comix *.CCMX|*.CCMX";
            DialogResult dr = saveDialog.ShowDialog();
            if (dr == DialogResult.OK)
            {
                byte[] array;

                //Save Image
                using (MemoryStream ms = new MemoryStream())
                {
                    Image img = pictureBox1.Image;
                    img.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
                    array = ms.ToArray();
                }

                using(FileStream fs = new FileStream(saveDialog.FileName, FileMode.Create))
                {
                    fs.Write(array, 0, array.Length);
                }
            }
        }

        //clear image
        private void clearImage_Click(object sender, EventArgs e)
        {
            pictureBox1.Image = null;
        }
    }
}

      

        
        
        
      

    

It's pretty standard. I have a test program that uses these methods. It opens the image in a pictureBox and then converts it to byte [] and clears the image of the PictureBox. Then you can hit Load byte [] and it will display the image correctly as it runs the ByteArrayToImage method.

Then, if I save the image from my other program and try to open it in a test program, it gives me a wicked "Parameter is not valid" error. Although both text documents are exactly the same as far as I can tell.