Parameter not valid exception when saving image from picturebox

I am trying to save an image from a picturebox1 element in a windows form, but the Image.Save method throws a parameter not valid exception and I can't work out why.

 string name = "BookCover_" + DateTime.Now.ToString("yyyyMMddHHmmss") + ".jpeg";
            string path = pathFolder + name;

            if (Directory.Exists(pathFolder))
            {
                pictureBox1.Image.Save(path, ImageFormat.Jpeg);
            }

This is the error message that I am getting:

    System.ArgumentException
  HResult=0x80070057
  Message=Parameter is not valid.
  Source=System.Drawing
  StackTrace:
   at System.Drawing.Image.Save(String filename, ImageCodecInfo encoder, EncoderParameters encoderParams)
   at System.Drawing.Image.Save(String filename, ImageFormat format)
   at LibraryProject.Forms.CameraForm.btnSave_Click(Object sender, EventArgs e) in C:\git\libraryproject\LibraryProject.Core\LibraryProject.Forms\CameraForm.cs:line 172
   at System.Windows.Forms.Control.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ButtonBase.WndProc(Message& m)
   at System.Windows.Forms.Button.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.Run(Form mainForm)
   at LibraryProject.Forms.Program.Main() in C:\git\libraryproject\LibraryProject.Core\LibraryProject.Forms\Program.cs:line 19