From my experience Cisco recommend this converter instead of the one available on your site.
https://collaborationhelp.cisco.com/article/en-us/WBX000026388
This converter didn't work for me and put out a black video.
There is no workaround and I have been made doubtful that Cisco are working towards one.
A pity/coincidence that their editor stops working and legacy no longer supported when they make the move towards MP4.
