My problem is related but different. I uploaded an iOS trailer that I was editing on iPhone. From iTunes, I saved it to my desktop then opened that file in iMovie. I did some editing and then wanted to put it back on the iPhone for continued editing but the only export option at that point is sending it to the Home Videos or Movies and is no longer editable on the iphone as it is now an .m4v file so even if I add it back to the file sharing Apps iMovie documents and sync my phone, it has an m4v extension unlike the other iMovie documents that have an .iMovieTrailer extension. Then, when I open it in iMovie on the iPhone the format is all messed up and I can no longer continue to edit it on an iOS device. So my question is how do I save a project in iMovie on an iMac to the .iMovieTrailer file type?