Invalid HTML Markup

[bcoplin]

For some reason our site has all of a sudden started producing an error. I will attach an image.
How can we fix this issue, it shows up on every page.

[prakash_s]

Hello @bcoplin,

Thanks for writing to us.

I checked your site it seems that it is working fine at the moment, please make sure you have not deactivated or deleted the required plugins. I would suggest you please clear your cache and then check it again. If the issue still persists please share the exact page URL.

Thanks