My idea is that you should post a proper problem report. Have a look over here:
You'll find many links in there that you will probably find useful over time. On the
subject of posting a proper problem report, do a string search on "problem report" in
there. You will find 2 links. Click them both, read what's there, & follow the advice.
In addition, try a string search on "video without audio" in there. You might find some
ideas that may help you. Video without audio & audio without video seems to be a way of
presenting multimedia content that is somewhere between rare & commonplace around the
web. Maybe you've hit one of those situations. But without a proper problem report, I'm