Digital Anarchy Installation Error on MAC or FCP

I have my Mac PC but my problem is regarding Digital Anarchy plug-ins for Final Cut Pro. The problem is I could not make the installers to work. I went to the Digital Anarchy website to uninstall the .sit file and when it created a folder on my desktop, I tried to open the .pkg file and the installer starts but an error appeared stating that the installer failed to open and install the file. What could this be? I sent an email in Digital Anarchy support but haven’t heard anything from them since yesterday. Can someone please help me?
