Web.config
First, you need to edit the web.config file of the SharePoint application. Open your web.config and add the httpModules
In the <system.web> section, find the <httpModules> element and edit it like the following:
<httpModules> <add name = “Session” type=”System.Web.SessionState.SessionStateModule”
/></httpModules>
You
also need to find the element tag <pages> (also under the
<system.web> element) and look for the attribute called
enableSessionState and set it to
true if it is currently false. Save and close the web.config file.
IIS7
- You should then open the IIS 7 manager, and select your web application.
- Open the modules applet under the IIS section.
- Click “Add Managed Module” in the right hand panel.
- Enter a name for the module, I chose “SessionState”, you can pick what you like, but I suggest something related to session state and then in the lower box, select the entry for:
System.Web.SessionState.SessionStateModule, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Made an IISreset, and test again. you can now add your WebPart Report Viewer control to your site.