Server Error: HTTP Error 500.19 - Internal Server Error

You might have come across this error while working on a WCF project on Vista, IIS 7.0 with Visual Studio 2005. Actually Microsoft has tightened the security on VISTA and most of the time it is annoying when it asks your permission. Following is the detail error message I received while trying to run a WCF project, however I found a simple solution to fix it.

Server Error

---

HTTP Error 500.19 - Internal Server Error

Description: The requested page cannot be accessed because the related configuration data for the page is invalid.

Error Code: 0x80070005

Notification: BeginRequest

Module: IIS Web Core

Requested URL: http://localhost:80/ProductsService/ProductsService.svc

Physical Path: C:\Test\ProductsService\ProductsService\ProductsService.svc

Logon User: Not yet determined

Logon Method: Not yet determined

Handler: Not yet determined

Config Error: Cannot read configuration file

Config File: \\?\C:\Test\ProductsService\ProductsService\web.config

Config Source:

-1:     0:

More Information...This error occurs when there is a problem reading the configuration file for the Web server or Web application. In some cases, the event logs may contain more information about what caused this error.

---

Server Version Information: Internet Information Services 7.0.

Solution: Compile the project and place the deployable files under C:\Inetpub\wwwroot\<projectname>. Make sure that the physical path of the respective Application (e.g. ProductsService in above error case) under IIS now points to new path. 

It looks like that if you run your application under IIS 7 and the physical path of any application is other than wwwroot then it will give the above error message or you provide that folder some special permission so that IIS can access it.

AJAX Error: 'Sys' is undefined

If you are using AJAX enabled web site or project, you may come across this error message. I got this error message too and spent few hours to fix this problem. I tried finding all possible solutions on Google and finally concluded with following three steps.
 

•  
  • Web.Config: Make sure your web.config is correctly configured to handle AJAX enabled request. You might have created a project which was not AJAX enabled earlier and now you want to Ajaxfy. The best solution is creating a new project ASP.NET AJAX Enabled Web Site. It will create a Web.config file by default. Compare this Web.config file with your other project’s Web.config file which is casuing the error. Make sure that you are not missing any new section. You can simply copy and paste it at appropriate place. For detail information you can also visit at  http://ajax.asp.net/docs/configuringASPNETAJAX.Aspx
  •  Using Master Page: If your ASP.NET web page is using a Master Page, make sure your Script Manager Control is placed in Master Page only. Content page should not be using Script Manager Control.
  • Regular Web Page: If you are not using a Master Page then each ASP.NET web page must have its own Script Manager Control.