I am working on developing an application with a DataModule in Delphi and I’m running into Access Violations when I reference the DataModule from the main form of the application It appears that DataModule1 is nil which would explain the AV error, but I’m not sure how to solve the problem given everything seems to be defined properly in each of the files.

Here is the main forms code (with AV line marked):

unit mainform;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
  System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs,
  Data.DB, Vcl.Grids, Vcl.DBGrids, Vcl.ExtCtrls, Vcl.Buttons, Vcl.DBCtrls,
  Vcl.StdCtrls, datamod;

type
  TForm1 = class(TForm)
    GroupBox1: TGroupBox;
    DBNavigator1: TDBNavigator;
    DBGrid1: TDBGrid;
    procedure Form1Create(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Form1Create(Sender: TObject);
begin
    left:=(screen.width-width) div 2;
    top:=(screen.height-height) div 2;

    with DataModule1.dbConnect do  // <---- This line gives the AV
    begin
        Close;
        with Params do
        begin
            Clear;
            Add('DriverID=SQLite');
            Add('Database=c:kkastencodedelphitestcasebatool.db');
        end;
        Open;
    end;
    DataModule1.FDQuery1.Open;
end;

end.

Here is the data module code:

unit datamod;

interface

uses
  System.SysUtils, System.Classes, FireDAC.Stan.Intf, FireDAC.Stan.Option,
  FireDAC.Stan.Error, FireDAC.UI.Intf, FireDAC.Phys.Intf, FireDAC.Stan.Def,
  FireDAC.Stan.Pool, FireDAC.Stan.Async, FireDAC.Phys, FireDAC.VCLUI.Wait,
  FireDAC.Stan.Param, FireDAC.DatS, FireDAC.DApt.Intf, FireDAC.DApt, Data.DB,
  FireDAC.Comp.DataSet, FireDAC.Comp.Client, FireDAC.Phys.SQLite,
  FireDAC.Phys.SQLiteDef, FireDAC.Stan.ExprFuncs,
  FireDAC.Phys.SQLiteWrapper.Stat;

type
  TDataModule1 = class(TDataModule)
    DataSource1: TDataSource;
    dbConnect: TFDConnection;
    FDQuery1: TFDQuery;
    FDQuery1MRS_Item: TIntegerField;
    FDQuery1MRS_Desc: TStringField;
    FDQuery1MRS_Amount: TBCDField;
    FDQuery1MRS_Actual: TBCDField;
    FDQuery1MRS_Adjust: TBCDField;
    FDQuery1MRS_NewAmt: TBCDField;
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  DataModule1: TDataModule1;

implementation

{%CLASSGROUP 'Vcl.Controls.TControl'}

{$R *.dfm}

end.