You have a few options when you don’t have access to a source map:

• Ignore the message. It generaly only gets thrown when your dev tools are open.
• Remove the reference in the original file. These are the last characters (comments) at the end of the file.
• Generate a source map yourself when you have access to the source code. For video.js, it can be generated from video.dev.js.
• Use a public CDN version which might not link to the source map.

There also is a discussion on GitHub about this topic.