unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type
  TLizenzDocument = class
    F_ID: string;
    F_Ref: string;
  public
    property _ID: string read F_ID write F_ID;
    property _Ref: string read F_Ref write F_Ref;
  end;
  TLizenzDocumentArray = array of TLizenzDocument;

  TForm1 = class(TForm)
    Memo1: TMemo;
    ListBox1: TListBox;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private-Deklarationen }
    function ConvertJsonToMobile5LizenzDocumentArray(AContent: string): TLizenzDocumentArray;
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;

implementation

uses
  System.Json,
  Rest.Json,
  REST.Json.Types;

{$R *.dfm}

{ TForm1 }

procedure TForm1.Button1Click(Sender: TObject);
var
  VLizenzen: TLizenzDocumentArray;
  I: Integer;
begin
  ListBox1.Items.Clear;
  VLizenzen := ConvertJsonToMobile5LizenzDocumentArray(Memo1.Text);
  for I := 0 to Length(VLizenzen) - 1 do
    ListBox1.Items.Add(VLizenzen[I]._ID);
end;

function TForm1.ConvertJsonToMobile5LizenzDocumentArray(AContent: string): TLizenzDocumentArray;
var
  VJSONArray: TJSONArray;
  VJSONValue: TJSONValue;
  VJSONObject: TLizenzDocument;
begin
  VJSONArray := TJSONObject.ParseJSONValue(AContent) as TJSONArray;
  Result := [];
  for VJSONValue in VJSONArray do
  begin
    //--- hier wird die Zugriffsverletzung geworfen ---
    VJSONObject := TJson.JsonToObject<TLizenzDocument>(VJSONValue as TJSONObject);
    Result := Result + [VJSONObject];
  end;
end;

end.