I've installed the same application and everything worked normally. I even loaded an MP4 file that fit on a DVD and proceeded with the burning phase. I've selected a Video DVD and the software automatically converted the file.
Therefore, make sure that you have the latest version of the software downloadable from the following link: https://www.winxdvd.com/dvd-author/
Secondly, the file that you have must not exceed the total size of the medium you're using (Blu-Ray, DVD, CD, etc).
If you can't hear any sound, change the code. Make it WAV, AAC or MP3.