Question

Using the following error handling in Application_Error():

    protected void Application_Error()
    {
        Exception exception = Server.GetLastError();
        Response.Clear();

        HttpException httpException = exception as HttpException;

        if (httpException != null)
        {
            string action;

            switch (httpException.GetHttpCode())
            {
                case 404:
                    // page not found
                    action = "HttpError404";
                    break;
                case 500:
                    // server error
                    action = "HttpError500";
                    break;
                default:
                    action = "General";
                    break;
            }

            // clear error on server
            Server.ClearError();

            Response.Redirect(String.Format("~/Error/{0}/?message={1}", action, exception.Message));
        }
    }

Prior to adding this, my pages rendered fine. Now that I’ve added this, I’m getting about 21 file not found exceptions. I initially thought that some routing values were wrong (but they don’t execute until you try the route), commented them out, same thing.

I stepped through the initial page load up, and since the entire page renders at once, once, I wasn’t able to trace down where these are coming from, and the stacktrace doesn’t give me what I’m looking for:

at System.Web.StaticFileHandler.GetFileInfo(String
virtualPathWithPathInfo, String physicalPath, HttpResponse response)
at System.Web.StaticFileHandler.ProcessRequestInternal(HttpContext
context, String overrideVirtualPath) at
System.Web.DefaultHttpHandler.BeginProcessRequest(HttpContext context,
AsyncCallback callback, Object state) at
System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step,
Boolean& completedSynchronously)

I thought that maybe this was occurring where the CSS and scripts are defined, but commenting these out did nothing to fix the issue.

How can I track this down?

Answer 1

I bet 5 bucks it’s the favicon.ico file that some browsers request and which you didn’t provide. Inside your error handler simply look at Request.Url property in Debug mode to see the requested url and you will know which file is missing. Also if you intend to redirect at the end of your error handler as you do, calling Server.ClearError(); doesn’t make much sense.