I am having the same issue, very frustrating. I don't think that you are missing anything. I'm using a mac mini with iMovie 10.0.2. I have a Sony HDR-XR500. I had previously been able to import with no problem into my MacBook pro with no problem. I upgraded to a new mac mini with a WD Thunderbotl 8TB external drive to store all of my home movies, as the files tend to be quite large, but I'm completely stuck. I've read through several posts on this topic in Apple support forums as well as online in general, and it does not appear that there is a solution for this problem. I hope someone can figure it out soon.