Tribute page Analyze HTML problem

Hello every body.
When i analyze(Analyze HTML on CodePen panel) the code HTML of tribute page, I get this message: HTML Inspector warning. Please I want to know what the message means.

Hmmm, not sure off hand. Can you post a link to your codpen?

This is a link:

If there was an error with any of your code they would follow that warning header. If nothing is displaying then you’re good.

There were errors in code. Thank you