Exact same problem here I disabled all of my antivirus software bitdefender (which kept detecting certain files in the installation as a virus) which I never had a problem with in previous versions of PR only 1.3 but even with it completely disabled still had the same error pop up.
And the virus Bitdefender keeps detecting files in the installation as "Gen.Variant.Barys.2494 I downloaded the installer multiple times to see if the same thing happened and the same thing happened everytime, like I said I never experienced this with PR before :s and I recently reinstalled PR aswell before 1.3