Invalid Pointer Operation freeing an object - delphi

Question

Being new to OOP, I'm curious why Delphi XE7 generated an invalid pointer operation on a logging class I was using whenI try to free it. So I created a simple test to create an object and then free it. I'm not sure what I'm missing here and why it throws this exception when MyObject.Free is called.
In the first unit, I create an instance of this object as shown here.
unit Unit1;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Unit2;
type
TForm1 = class(TForm)
Button1: TButton;
Button2: TButton;
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
MyObject: TMyObject;
implementation
{$R *.dfm}
procedure TForm1.Button1Click(Sender: TObject);
begin
MyObject := TMyObject.Create;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
MyObject.Free;
end;
end.
In the 2nd unit, I have the object defined as follows.
unit Unit2;
interface
uses System.Classes;
type
TMyObject = class
public
constructor Create;
destructor Free;
end;
implementation
constructor TMyObject.Create;
begin
inherited Create;
end;
destructor TMyObject.Free;
begin
inherited Free;
end;
end.
Any help is appreciated.

Answer 1

Always implement a destructor by overriding the virtual destructor named Destroy.
type
TMyObject = class
public
constructor Create;
destructor Destroy; override;
end;
constructor TMyObject.Create;
begin
inherited;
end;
destructor TMyObject.Destroy;
begin
inherited;
end;
To destroy an instance call the method named Free in TObject. This calls the virtual destructor Destroy only if the instance is not nil.
Learn more from the documentation:
http://docwiki.embarcadero.com/Libraries/en/System.TObject.Free
http://docwiki.embarcadero.com/Libraries/en/System.TObject.Destroy
The name MyObject is weak. Object is used for instances. Class is used for classes.