I debugged the asp.net website locally and introduced a single sign-on httpmodule,. The problem is that after a successful login, I have to jump back to the url before login (that is, the root directory of the domain name, the response should be default.aspx). Now I have to return a 404 directly, and I need to type default.aspx before I can access it.
I can access the module by removing the single sign-on module. I don"t know if this is the problem. When I step into debugging, there is no problem inside the module. I feel that the problem lies outside the module code. I follow the code into the System more and more messy.
this is my first time to use asp.net

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