Question

I never noticed it in my program before, but for one of my TForm I have a destroy event, which frees an object, is called or fired more than once. I don’t understand why.

procedure THTrendFrm.FormDestroy(Sender: TObject);
begin
  LogAlarm.Free;  <---Invalid Pointer Operation exception is raised
end;

Thanks in advance,

Update: Here is the FastMM message window right after my program is shutdown.
TAlarmMsg is the class from which LogAlarm is created.

Answer 1

Thanks to David Heffernan and others. I found my problem and fixed it. The TForm in question was being created twice in my project file like so.

Application.CreateForm(HTrendFrm, HTrend);

That explains why destroy was called twice.

Once I removed the duplicate line, it is shutting down fine.