Managed Metadata navigation is an awesome new feature in SharePoint 2013, but with learning new features there are always some growing pains. I learned an important lesson today- Be careful when setting your friendly URL’s. When a term has the same name as a subsite, the navigation to the page targeted by the term itself is fine, but for all the child terms, you get a “Page not found” message. For example, I will create a subsite called Test. Now I create a term called “Test” and I create child term called “Link1” which redirects to /test/Pages/Testlink1.aspx. If I set the navigation to term-driven (Using Friendly URL’s and Target Pages) I cannot make the friendly url the name of the subsite (in this case Test). If I do put Test as the friendly URL I can still go to the top link in the navigation bar, but any child terms will not function correctly as this is a naming collision.