The Application Pool or Managed Metadata Web Service may not have been started. Please Contact your Administrator

http://www.dotnetsharepoint.com/2013/10/the-application-pool-or-managed.html 

Managed Navigation SharePoint 2013 - Friendly URL

https://support.office.com/en-in/article/Enable-managed-navigation-for-a-site-in-SharePoint-49a067dc-77d2-455d-9e77-250ec7cc0a6d

https://technet.microsoft.com/en-us/library/dn194311.aspx