Application_Error() cannot access Session if the error is HTTP 404

[in10se]

I have the following code in my global.asax file:

void Application_Error(object sender, EventArgs e) 
{
     string ex = Server.GetLastError().ToString();
     HttpContext.Current.Session["HttpContext_ERROR"] = HttpContext.Current;
     HttpContext.Current.Session["LastError"] = ex;
     // this just logs various info about the error
     ErrorLogger.LogError("Uncaught exception", ex, HttpContext.Current);
     Server.ClearError();
}

This works just fine for HTTP 500 (Server Error) errors, but if it's a HTTP 404 (File Not Found) error, the Session is always null. Why? Is there any way to read or write to the Session in Application_Error for a 404?

[Frinavale]

I have the following code in my global.asax file:

void Application_Error(object sender, EventArgs e) 
{
     string ex = Server.GetLastError().ToString();
     HttpContext.Current.Session["HttpContext_ERROR"] = HttpContext.Current;
     HttpContext.Current.Session["LastError"] = ex;
     // this just logs various info about the error
     ErrorLogger.LogError("Uncaught exception", ex, HttpContext.Current);
     Server.ClearError();
}

This works just fine for HTTP 500 (Server Error) errors, but if it's a HTTP 404 (File Not Found) error, the Session is always null. Why? Is there any way to read or write to the Session in Application_Error for a 404?

The HttpContext object is created by ASP.NET during the page request. Since no page was found, no HttpContext Object can be created; therefore, no Session can exist when a 404 error occurs.

-Frinny