During the last three years I have installed Handbrake twice to convert a just created WMV to H.264/AAC. On both occasions Handbrake just failed to do anything

During the last three years I have installed Handbrake twice to convert a just created WMV to H.264/AAC. On both occasions Handbrake just failed to do anything for the file and I ended up uninstalling it. Later I created a kilometer long ffmpeg command line and been happily creating files to be used with Flowplayer. Those files have been playing without any issues on iOS, Android, Windows, Linux and MacOSX. I wonder why this Windows Live Movie Maker output turned out to be problematic for Handbrake, but on the other hand now I haven't needed to start any video conversion GUI for a long time.