UHD Converter Unifab not converting the video from UHD mkv file

[mopgcw]

I was able to successfully use DVDfab to create the mkv file from the disc for Wonka. This mkv file plays fine in VLC. When trying to use Unifab to convert the mkv to an m4v file for ipad pro selecting the default device option, it creates the file, but the video is missing/black. just audio shows up in itunes.

Any advice?

thanks