You have discrepancy between Unit1.pas and Unit1.lfm (code and form).
In your Unit1.pas you don't have declaration for PanelBtnEXIT, so add it, ie. in line 27:
type
{ TForm1 }
TForm1 = class(TForm)
BtnEXIT: TButton;
BtnGenerate: TButton;
BtnRestart: TSpeedButton;
LabelCLOCK: TLabel;
PanelTOPgrid: TPanel;
PanelLEFTgrid: TPanel;
PanelTIME: TPanel;
PanelBtnEXIResetGameT: TPanel;
PanelBtnRestart: TPanel;
PanelBtnNEW: TPanel;
PanelNUMBER: TPanel;
PanelStringGrid: TPanel;
PanelButtons: TPanel;
PanelBtnEXIT: TPanel; // <-- add this line
...
Then change line 133 from
BtnExit.SetBounds to:
PanelBtnEXIT.SetBounds // <-- change this line
(PanelBtnNew.Left + PanelBtnNew.Width + Spacing,
(PanelButtons.Height - ControlHeight) div 2, BtnWidth + 50, ControlHeight -20);
I didn't check if you are missing some other declarations from form. Normally, form and source are synchronized.
P.S.: added explanation in code and comment at the end.