IE hang when access some web sites with Proxy.pac

  Recently we worked on several IE hang cases which have similar symptoms, let me share our finding and solution.   Symptoms ========   Internet Explorer hangs for minutes before web page can be displayed. It happens on several internet web sites.   No issue if IE set proxy server directly instead of proxy Pac…


Unable to organize favorites in IE8

  After applying following Group Policy setting, users are unable to organize favorites in Internet Explorer 8.   User Configuration->Administrative Templates->Windows Components->Windows Explorer ->Prevent access to drives from My Computer (Restrict C drive only)   IE favorites location is under C:\Documents and Settings\*USERNAME*\. When above GP is enabled, it is the expected behavior.   In…


Internet Explorer Fails to open PDF file

Occasionally, Internet Explore fails to open PDF file using Adobe Acrobat Reader and displays a blank screen.   In the network monitor trace, it shows that client side receives the PDF file from server and logs Http 200.   From process monitor log, it shows the Internet Explorer fails to open pdf documents due to…


A “404 File not found” issue caused by ASP.NET v4.0 Extensionless URL feature on IIS 6.0

    Symptom =======   After IIS is restarted, my customer received “404 File not found” error when he tried to visit his web site, e.g http://servername/ . If he visited http://servername/index.htm, he would get the page successfully. The failed request in IIS log is: 2011-12-01 09:38:43 W3SVC1 GET / – 80 –…


How to develop and deploy ActiveX control in C#

How to develop and deploy ActiveX control in C# There are lots of documents regarding how to develop and deploy an ActiveX control in native code(VB, C++, Delphi, …), however there’s few documents describe the manual in .NET. With this manual, you will learn how to develop, sign and deploy an ActiveX control with C#.NET….


IIS 7+ Kerberos authentication failure: KRB_AP_ERR_MODIFIED

KRB_AP_ERR_MODIFIED is a common Kerberos failure message. This means some encrypted Kerberos authentication data sent by the client did not decrypt properly at the server. When a Kerberos client requests a ticket for a specific service, the service is actually identified by its SPN.  The KDC grants the client a service ticket that is encrypted…


Why we get the exception “Failed to load viewstate”

Background When we try to add controls dynamically during the post-back request for an ASPX page,   we may get below error: Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request. For example, when adding controls dynamically,…


The first WCF call always timed out?

This is a scenario where both the WCF client and service are running in the same AppDomain inside a MVC application. The WC F call originates from MVC controller. In addition, the WCF service host was created in the same function as well. The code looks like:  public ActionResult Index() {             //Create the service…


IIS returns 400 “bad request” for WCF service file

This is an IIS hosted WCF service uses basicHttpBinding in NLB environment. The configuration looks like below. It had been worked well for years. <service name=”MyService”>     <endpoint address=”https://NLB_Virtual_Name.Organization.Company.Com/MyService/MyService.svc” binding=”basicHttpBinding”     contract=”IMyService”…./>      <endpoint contract=”IMetadataExchange” binding=”mexHttpBinding” address=”mex” /> </service> After applied .Net 3.5 SP1, IIS returns 400 every time browse to follow URL in browser. https://NLB_Virtual_Name.Organization.Company.Com/MyService/MyService.svc…


WCF Exception: Security settings for this service require ‘Anonymous’ Authentication but it is not enabled for the IIS application that hosts this service

Windows authentication is well suited for scenarios in which your users have domain credentials. Using basicHttpBinding with TransportCredentialOnly security mode option, users are authenticated by using Windows authentication. Here is an article described how to implement this. How to: Use basicHttpBinding with Windows Authentication and TransportCredentialOnly in WCF from Windows Forms These two blogs…