WCF Error: The configuration section system.web.extensions cannot be read because it is missing a section declaration

Last Reply one year ago By dharmendr

Posted one year ago


I have WCF Service Project which is in .NET version 3.5 (VS2008) and the running pool is Classic .NET App pool, to Upgrade to .NET version 4.0, Project Migrated to VS2010, then in IIS Manager when Classic .NET App pool was selected there is an Error message while opening "Directory Browsing". the Error Message is adding below

"The configuration section 'system.web.extensions' cannot be read because it is missing a section declaration"

The Error Message is not appearing when selected any other App pool.

after Upgradation is it necessary to change app pool to ASP.NET v4.0 Classic .NET AppPool or Some other.
anyway i tried every App pool. when selected App pool ASP.NET v4.0 Classic .NET AppPool , while browsing .svc file the following Error is displaying

"Screenshot of browser when APP POOL is "ASP.NET v4.0 Classic .NET AppPool"".

Posted one year ago

thank you for the reply, the error message is not showing, but still the output is not expected.this is what i get when the .svc file is browsed.


HTTP Error 500. An internal server error has occured.

please help 

Posted one year ago

i hope everything is okay. if iam not doing correctly please correct me