This error can occur if not all the correct components are installed on the server. For Server 2012 onwards, the "Web Server (IIS)" and "Application Server" roles be installed as well as the optional "Web Server (IIS) Support" under "Application Server" (this needs to be selected during the process of installing the Application Server role).
NOTE: Installing this may break .NET's integration with IIS, meaning that .NET 3.5/4.5 will need to be reinstalled afterwards, see above.
More details here: http://stackoverflow.com/questions/9794985/iis-this-configuration-section-cannot-be-used-at-this-path-configuration-lock