w3c html validation error - Section lacks heading. Consider using h2-h6 elements to add identifying headings to all sections

Either:

1. Add a heading (h1, ..., h6) tag to your section element.
2. Replace your section element with a div element.
3. Ignore the warning. The message you're seeing is a non-normative usage recommendation, as per the HTML5 spec (highlighting mine):

   The theme of each section should be identified, typically by including a heading (h1-h6 element) as a child of the section element.

Your code is valid (if you use a closing </section> instead of </div>).

The W3C validator reports a warning, not an error.

While it is useful to provide a heading for each sectioning content element, it is not required.

The only way to prevent this warning when using sectioning content elements is, well, to follow the advice by providing a heading content element. If you’d use a div instead, your document outline would be different and likely wrong (if you used section correctly in the first place).