MS Access Code was working but now gives error message. Please kindly help. Thanks a lot

Hi Supers
Attached are the codes with error. These codes were fine did not give me any error, now it does.
Thanks a lot
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Option Compare Database

Private Sub ExitBtn_Click()

    If MsgBox("Are you sure you want to exit?", vbQuestion + vbYesNo, "Quit Program") = vbNo Then
        Cancel = True
    Else
    DoCmd.Quit
    
    End If

End Sub

Private Sub Form_Load()
   username = Environ("COMPUTERNAME") & "." & Environ("USERNAME")
   DoCmd.SetWarnings False
   DoCmd.OpenQuery "LogOnQ"
   DoCmd.SetWarnings True
End Sub

Private Sub Form_Open(Cancel As Integer)

      DoCmd.Maximize

End Sub

Private Sub Form_Unload(Cancel As Integer)
   DoCmd.SetWarnings False
   DoCmd.OpenQuery "LogOffQ"
   DoCmd.SetWarnings True
End Sub

Thanks