Youtube Download Video Error

1. Check if the proxy address is filled in correctly. The correct proxy address is in the form of http://127.0.0.1:port_number. Do not fill in random content.
2. Youtube video downloads are two files that independently download the video screen and audio, and then merge them into mp4. If you open one of the video files during the download process, then there is definitely no sound. Please wait patiently for the download to complete and merge.