Trouble Deploying .Net Framework 4 Website on IIS7

Question

Okay, I am trying to deploy a .Net framework 4 website on IIS7 server. I have already changed the application-pool's target framework to .Net 4, but the app is still showing me the error:

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

I am guessing that has something to do with the new feature of .Net4 that lets me have a compact Web config file. I think for some reason IIS7 is not happy with this.

What can I do to deploy this app successfully or do I have to scale back to v3.5? I am sure there is a solution out there.

Do you have any suggestions?

Answer 1

I could solve this issue myself after some hunting around (happens!).

apparently has nothing to do with the way the config file is structured, it is the assembly for ASP.Net Ajax which is not deployed on my target server but might be present on my dev machine.

I deleted the entry from the web.config file and this issue was resolved, there were some other minor issues but nothing worth mentioning.

The deployment experience for IIS7+.Net Framework 4 wasn't too difficult and the added capabilities will going to be worth it.

Answer 2

You can also get this very same error if you create a new website in IIS 7(.5) as the application pool it creates for the new site may still be set to 2.0, and as such, system.web.extensions is not valid in a 2.0 configuration file.

Simply go into IIS Manager, choose the application pools, select the one for your app, right-click, Advanced Settings and set .NET framework version to v4.