Just spoke with someone who had the exact same issue as you. We had already gone through the fixes you had tried but after a while of fiddling he found a solution. To fix it he dragged the contents of the .ZIP into another folder (Desktop, Documents, Downloads, etc..). This seemed to have fixed the problem entirely. I may add that just copying and pasting the contents somewhere else should work too. Hopeful, this fixes your issue.
well thats strange didnt work for me