Ok, that's very strange. Do you mind telling me where in the world you are located and/or if you ever have this problem with other downloads?
I have placed the file on my Google Drive and you can get it here:
https://drive.google.com/file/d/0B7b4Un ... sp=sharingAlso, if you are comfortable with Git then you can get the system straight from our Git repository. I realise this approach may not be for everyone:
https://bitbucket.org/volumesoffun/cubi ... or-unity3dLet me know if you have success with either of the above.