If you see this message:
It means you first have to uninstall the application from your control panel and then try installing again. For Macs, delete the application by moving it to trash from the Applications folder.
It does this because the application was installed previously and the new version has a newer digital security certificate that is incompatible with the older one. Why they felt it was helpful to present this message for that problem is hard to understand, but that's what it is.
Note: Sometimes you uninstall the application and you still get this message. Every time this has happened we've traced it to another copy of the application, sometimes on a backup disk that isn't even mounted. So, you will need to be thorough about tracking down the old ones.
