Robiniwitz

Definitely shows up as fully downloaded. I have deleted and re-downloaded several different Platform Packs with exactly the same outcome. I get the same pop up screen as tbjorn81 posted above.  Also as mentioned, I made sure my language and location settings were English/US and had my antivirus completely disabled. (at one time, I actually removed my antivirus, restarted and tried again with the same result)

Any other ideas I can try??

Seeing this very same issue.  I've made sure the US/English is set correctly as well as not just disabled (didn't work), but outright removed my antivirus and  the issue remains. I've tried several various platform packages with the same result.

This is painful.