ASP.NET Web Application gives HTTP Error 500.21 - Internal Server Error.


I have hosted a WEB Api application in local and on "Browse" i am getting below error. Pals, Please help on it.

Error Summary HTTP Error 500.21 - Internal Server Error

Handler "ExtensionlessUrlHandler-Integrated-4.0" has a bad module "ManagedPipelineHandler" in its module list

Detailed Error Information

Module IIS Web Core

Notification ExecuteRequestHandler

Handler ExtensionlessUrlHandler-Integrated-4.0

Error Code 0x8007000d

Requested URL http://localhost:8082/

Physical Path D:\WEB API Publish

Logon Method Anonymous

Logon User Anonymous

Most likely causes: •Managed handler is used; however, ASP.NET is not installed or is not installed completely. •There is a typographical error in the configuration for the handler module list.

Things you can try: •Install ASP.NET if you are using managed handler. •Ensure that the handler module's name is specified correctly. Module names are case-sensitive and use the format modules="StaticFileModule,DefaultDocumentModule,DirectoryListingModule".

asked on Stack Overflow Sep 9, 2015 by Prasanth Aman

1 Answer


I ran into this error when .NET 4.5 was installed but not under the IIS role. Try following these steps:

  1. Open Server Manager -> Add Roles and Features.
  2. Click next until you get to the “Server Roles” page.
  3. Scroll down to “Web Server (IIS)” and expand it.
  4. Expand Web server -> expand Application Development.
  5. Check the option for ASP.NET 4.5 and hit yes to the additional components pop-up.
answered on Stack Overflow Sep 14, 2015 by user1876085

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