http://avid.force.com/pkb/articles/en_US/download/en423319
In case anyone is interested in importing DNxHD footage (potentially from Resolve for instance), you have to install the Avid codec first. I forgot you had to do this, and kept getting an error message saying I had a faulty installation of Quick Time, which doesn't even work on Windows 10. In my case, I was bringing in a QuickTime .mov file from Resolve, DNxHD 1080p.