When I try to open one of these files, Video Splitter displays the message "Some files are not supported or damaged". I can send you a screenshot if that helps, although I'm not quite sure of how to attach pictures in this forum, I'd have to figure it out.
This happens with most of my WMV files, which are fine and can be played in VLC without problems.
By the way, I'm using Video Splitter 7.6 (I'm not interested in version 8).