Video and audio are set to output as "copy". I saved one clip in its native MP4. Now, it will only save to .MKV -- even if I force it to MP4 in video settings. What the H*** is going on?
Is more than a single one instance of Avidemux running? The H*** which is going on gets logged to %localappdata%\avidemux\admlog.txt, in doubt compress (7z, zip or gz, no rar please) and attach this file to your reply.