What is server problem 400 in YouTube?

“When switching from an Android Applications that uses webView and the Intent function to watch YouTube videos with the YouTube app I receive a “There was a problem with the network [400]” error. … You need to replace the direct YouTube video link to just the video ID itself. It works every time.

For More Information Please Refer: https://www.imobie.com/support/how-to-fix-youtube-error-400.htm