OpenStreetMap maps actually appear

An OpenStreetMap map used to leave an empty rectangle on the page, and nothing said why. Three separate reasons could produce that same blank box, and none of them told the viewer anything.

The map now has a size. A map is drawn into whatever space its container has, and that container had no height at all unless the page author happened to give it one — so a map that had loaded perfectly and was working correctly was still nothing to look at. It now comes with a sensible default height, and a page that wants a different one still just says so.

A map that cannot be drawn explains itself. Where the map's own drawing code cannot be fetched, the page now shows the same short notice the portal already uses for any view that fails to render: what happened, a suggestion to reload, and the technical reason — including the exact address that could not be fetched, so the problem can be reported and fixed instead of guessed at.

Leaving the page is no longer a failure. Navigating away while maps are still being drawn cancels that work, which is entirely routine — but it was being recorded with the same severity as a map that genuinely failed. Ordinary navigation is now recorded as what it is, which means what remains under that heading is worth looking at.