We are attempting to modify the audio on a movie, add a new sound file and remove the existing. removing is easy but the file is then unloadable to advidemux it also says it can't fine a demuxer for the audio files which are MP3
Files are too large to attach, you may request them if you wish by email
To add an external audio track, please use "Audio" --> "Select Track" and choose ".... Add audio track" from the dropdown menu of an enabled track. The path "File" --> "Open..." is for video files only.