HTTP Error 503. The service is unavailable. App pool stops on accessing website

There are number of posts on this and I have tried many a things by now. But to no avail. Myself a Winforms Developer basically, started working on this Web stuff few days back as my company is taking Web initiatives.

I have a ASP.Net project and I want to host it on local IIS. In Project properties -> Web settings I chose Use Local IIS Server and gave a url as localhost/MyApp. I tried accessing it on my firefox browser and received error as HTTP Error 503. The service is unavailable.

Previously I got many other errors and I one by one fixed them all. But struck with this one. These are the settings I have in my project

  1. Application Pool set to ASP.Net v4.0 Classic
  2. App Pool Enable 32 bit Application property is true
  3. App Pool is started
  4. Project build property set to Any CPU for Target framework

But I would like to mention a weird behavior. Following is something that I am facing

  1. Application Pool is Started
  2. I try to access my local website (by giving url as localhost/MyApp)
  3. I receive the error as HTTP Error 503. The service is unavailable
  4. Application Pool is Stopped

I have seen following link and I have already tried it. For the above behavior I reached here. According to this link, Computer name should not have . in it. I don’t have any . in my Computer name but do have - in it. Also my domain name contains . in it. Moreover I can’t change these settings as its my office laptop and our TFS settings are bound to our Domain and Computer Names.

Can anyone help me to understand whats happening? Please guide me. Thanks.


I have following code in Global.asax. Application_BeginRequest method is empty in same file.

protected override void Application_Start(object sender, EventArgs e)
    base.Application_Start(sender, e);
    String _path = String.Concat(System.AppDomain.CurrentDomain.RelativeSearchPath, ";",
    System.Environment.SetEnvironmentVariable("PATH", _path, EnvironmentVariableTarget.Process);
    MyAppLog.WriteMessage("Application Started");


As per the suggestions in Comment, I am able to run the website from Cassini.

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