as you may notice in the attached picture I use several mods for faster "nice building", so perhaps there is a conflict between these mods. However, maybe somebody knows the problem and has a suggestion what to do. Or maybe I miss a precondition, even that none is mentioned in the UI.
I'm not able to build a pearl fishing (I use the german version, don't know the english terms). I tried all options: the island provides pearls, the island provides pearls plus "seads" in the harbours office, and at last (see image) the island does not provide pearls plus "seads" in the office.