Note to self :

Whenever you want to create a SharePoint Site bases on a Web Database template, you have to make sure you did the following:

• Created a Access Service Application
  (Central Administration – Manage Service Applications – New – Access Services)
• Started the Access Database Service
  (Central Administration – Manage Services on Server)

If you don’t you will receive an error like this:

Preparing Site …
Someone has recently made changes to this site and the site is being updated. If the site remains offline for an extended period of time, contact a site owner.

Wait a moment and refresh your browser

Don’t bother waiting…

After you did all of this, open up the SharePoint 2010 Management Shell, and give the following command:

enable-spSessionStateService –DataBaseName <SomeNewDatabaseName>

This will create a session state database and turns on the session state service.