Running El Capitan on MacBook Air. Installed Adapter to export a short video file I created in IMovie 120MB, 80-second ad to a format other than MP4. I'm having problems uploading it to Etsy and wanted to try other formats.
However, when I drag and drop the MP4 file and select MPEG output, the conversion seems to go fine, but only the first few seconds or so of the entire bit gets converted. I've tried your FAQ and Q&A and found no hints. Help?