It is possible that your download ended prematurely for a variety of reasons (internet connectivity, download manager software problems, download bandwidth issues).
This can cause the file to be corrupted in your browser cache, so even if you download it again, it remains corrupted.
The solution to this is to download a fresh copy with a different file name.
Please download the new file here.
Once you download and install this copy and all should be fine. If you are still having problems, please contact our support team.