What does your client has issued a malformed or illegal request mean?

The error message is rather ambiguous and reads “Your client has issued a malformed or illegal request. That’s all we know”. Looking at the status code, the error seems to indicate that Youtube serves is incapable of processing your request due to a client error.

For More Information Please Refer: https://appuals.com/fix-youtube-error-400-client-has-issued-a-malformed-or-illegal-request/