LazyInitializationException after upgrade to IIS 7.5

Question

We develop a ASP.NET 4.0 / MVC 3 web application, using Active Record as database abstraction.

To be able to use lazy relations inside views, we are using the SessionScopeWebModule from ActiveRecord documentation here.

The app works fine on our current Win 2003 / IIS 6 machine, but only on our new Win 2008 R2 / IIS 7.5 it throws a LazyInitializationException when a controller or view tries to access a lazy relation. After changing to manual session handling (also explained in the doc link above), it works again.

I wonder what the difference is, as the manual states that both approaches do basically the same thing.

Answer 1

When running an ASP.NET app in IIS 7+ in integrated pipeline, you need to register the http modules under the system.webServer / modules section of web.config.

It's possible to have a single web.config for both IIS 6 and IIS 7+, see this article.

Otherwise, run in classic pipeline mode, it will behave just as in IIS 6.