What’s the website problem your audit tool found—but didn’t help you fix?

We built SiteCheck Pro because most website audit tools are very good at identifying problems, but the work often begins after the report arrives. I’m curious about the other side of that experience:

What website issue have you discovered that was difficult, expensive, or time-consuming to actually fix?

SEO? Accessibility? AI visibility? Indexability? SEM/PPC readiness? Something else?

SiteCheck Pro launches tomorrow, and I’d genuinely like to hear what people have run into. I’ll be here personally reading and responding.