Apple recently updated their iMoviesoftware to version 10.
Due to changes in the way that iMovie Projects are now created, this new version of iMoviedoes not work with the "Edit with iMovie"export button in Elgato Video Capture.
If you want to bring video into iMovie 10, please take your completed Elgato Video Capture recording from the Movies folder in OS X, and manually add it to your iMovie Project.
If you continue to use an earlier version of iMovie, like iMovie 9, then you can still use the "Edit with iMovie"export button in Elgato Video Capture.