When I export my epub file, I get a message saying that the TOC anchors were not found. I have been researching this for over two hours now, so I'd appreciate any help. When creating the TOC, I have ticked the box that generates anchors in the source text. I have instructed that the TOC use a given header style. The TOC generates fine, however, it is not interactive. Despite having checked the right buttons (as far as I can see), there are no anchors being generated.