Don't install the zip via the WP dashboard. Extract it and FTP it to your domain. The license key is in the zip file.
follow Sab3L44's advice. The plugin works.
I just used the license key and is able to download update to 1.7.11
Here's a share for the original file v1.7.8 with license key.
Magic Button :
Code:
http://www25.zippyshare.com/v/63910117/file.html