PNGImage "Access violation" error at procedure end - delphi

Question

I am using PNGImage library in my project, which entire GUI is made up of .png images, which i loaded to TImages at run-time. For some purposes i have to dynamically create plenty of components groups that are similar to each other. Every group consists of some TImages and have a button that lets user proceed to another page with more details about clicked item.
The code i am using:
procedure TMain_Frame.selection_click(Sender: TObject);
var id: string;
begin
id := StringReplace(TLabel(sender).Name, 'label_item_select_', '', [rfReplaceAll]);
hide_created_components; // It does Free all components
show_details(id);
end; // (1)
Access violation error occurs at (1). The odd thing is that it happenes completly random: error may happen at the very first click or may not happen for 10 clicks. If no error occured, F8 leads me inside PNGImage library where some stuff is done. However when error occurs, F7/8 immediately throws it without doing what it has to. This problem happenes only when i go from dynamicaly created objects to static.
CPU window shows that error occured at this ASM code:
movzx ecx, [edi]
ecx value is 755A2E09, edi is 00000000
Is it correct to .Free all dynamically created components? Or should be .Destroy used instead? And why does PNGImage goes inside itself on procedure end;?
Demo:
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, pngimage, ExtCtrls;
type
TForm1 = class(TForm)
Button1: TButton;
Image1: TImage;
procedure selection_click(Sender: TObject);
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure create_label;
var Button: TLabel;
begin
Button := TLabel.Create(Form1);
with Button do
begin
Name := 'dynamic_label_1';
Parent := Form1;
Autosize := false;
Left := 100;
Top := 100;
Width := 150;
Height := 20;
Caption := 'Dynamic Label: Click Me';
BringToFront;
Cursor := crHandPoint;
end;
Button.OnClick := Form1.selection_click;
end;
procedure hide_dyn_label(L: TLabel; mode: boolean);
begin
if mode then
begin
L.Free;
Form1.Image1.Picture.LoadFromFile(PAnsiChar('button_close.png'));
Form1.Image1.Visible := true;
end
else
create_label;
end;
procedure TForm1.selection_click(Sender: TObject);
var id: string;
begin
id := StringReplace(TLabel(Sender).Name, 'dynamic_label_', '', [rfReplaceAll]);
Form1.Button1.Visible := true;
hide_dyn_label(Form1.FindComponent('dynamic_label_1') as TLabel, true);
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
create_label;
Form1.Image1.Visible := false;
Form1.Button1.Visible := false;
end;
end.

Answer 1

You are freeing the TLabel while still in its OnClick event handler, Selection_Click which calls hide_dyn_label() which calls L.Free. You can't do that. Use some kind of delayed destruction, f.ex. with a boolean variable FreeDynLabels which you can check in Application.OnIdle. Or post a custom message to the form.