Salutations, This one caught me by surprise so I'm posting it hear for "open dialog"... I've been running some extensive ASP.NET v4 IIS7 Integrated mode 'Session' tests. ASP.NET Health Monitoring is often showing errors with the expired sessions. If you crawl the net or any of the Microsoft support forums you can see this is a wild one to nail down at times. Up until today I had only been debugging the root web.config with Visual Studio 2010. That's fairly common. I decided to, just for the heck of it, run the IIS7 Manager and take a look. As you no doubt know the IIS7 Manager reads and writes from the root web.config and if there are errors it often can not read from sections or make changes to them. Well..Using the IIS7 Manager I couldn't access any of the Session tools. What da heck! ;-) Turns out VS2010 added a section that was being duplicated: Removing this entire section, after <system.web>, corrected this: <assemblies> <add assembly="System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" /> <add assembly="System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" /> <add assembly="System.Data.DataSetExtensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" /> <add assembly="System.Xml.Linq, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" /> </assemblies> ...Caught me by surprise so I'm posting it here, just in case. All the best, Mark
