There's a problem with one of your CTAs. Try removing and re-inserting with the CTA insert tool. Learn more.
This error appears when you try to publish a new blog post or page and there's an issue with a CTA added to a rich text area. This error generally results from the CTA code breaking from being in the rich-text area.
To resolve, remove the CTA and re-add it to the rich-text area. If the issue persists, you can reach out to HubSpot Support here.