The config file contained in this addon in fact expands the Polaris system by four planets, but without a corresponding planetary config file for the world 'Polaris VII' resulting in an untextured 'obj1' appearing at the edge of the solar system. Nor are any bases or new scenarios provided.
As with the other two files in the Polaris series the author did not include a readme file to explain installation.
The correct order of installation, would seem to be Polaris.zip, 6 planets.zip and then New Polaris.zip