[Windows 10 Update KB4338819 issue] Conversion Failed. The transcoder exited due to an error

This is actually the subject of most of the posts in this thread and it was in this thread that this issue was unearthed and the windows updates identified !

Yes Microsoft issued a bad windows update which resulted in some 127.0.0.1 requests made by the Transcoder fail - Microsoft, 6 days later, released the 2nd windows update which fixed it and that is the one in your link