"This report failed to load because session state is not turned on" error in SharePoint 2010

By default, Session State is disabled for normal SharePoint 2010 installations and this typically causes problems with Access Services, Excel Services and SSRS reports.  To enable Session State, follow these steps.

Enable Session State using PowerShell

1. Open PowerShell from Start, All Programs, Microsoft SharePoint 2010 Products, SharePoint Management Shell.
2. Enter Enable-SPSessionStateService –DatabaseName "SPSessionStateDatabase" in the command window and hit ENTER.  Note, the database does not have to be named 'SPSessionStateDatabase'.
3. Restart IIS from a command console by typing iisreset and hitting ENTER.

     After enabling Session State, a quick (and fictitious) SSRS report is now displayed properly.