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

Question

I am getting error (The configuration section system.web.extensions cannot be read because it is missing a section declaration) while installin

Answer 1

I also had the same problem after upgrading my OS from Windows Server 2003 to Windows Server 2008 R2 , I just changed the application pool settings to .NetFramework 4.0.0 and also changed the classic to Integrated mode ... my problems solved ..