The previous version had some issues which have been fixed in the latest version and you can download it from here
To manually update the theme,
1) Activate some other theme.
2) Delete the existing Supernova theme (don’t worry you wont loose settings)
3)Upload and activate the new theme(in zip file).
Supernova Themes offer free WordPress themes for use with any type of website – non profit, hobby, or commercial websites .
Its totally free – no charges whatsoever.
The code has been tested in all of the major browsers and platforms.
Feel free to use them on any type of project – or alter them as much as you need to.