VB Application exiting

Hello

I am currently converting a VB 6.0 Application to VB.net. The VB.net application will Start up ; I can enter my User ID/ Password and then it just exits

The Main line code is as follows:

Public Sub Main()
    On Error GoTo Startup_Err
            
   Application = New CApplication
   Application.Create(APPLICATION_MODEL)
            
   'run the application
   Application.Run()

Startup_Exit:
        Exit Sub

Startup_Err:
        'if there is an error at this point it is fatal
        End
            
End Sub

The program goes to Exit Sub, End Sub then exits completely

Any Idea why this is happening ???