So a neighbour of mine set up a road using milestones some time ago. It's been very useful and I've started extending by laying some paved stone. Now I want to extend the road so I go to the last mini-milestone, right click and "Extend" is one of the options. If I click it, I can create a new mini-milestone. The only problem is that when I do, the road doesn't extend and the new mini-milestone seems to be a road of its own. The only option on it is "Extend" when I right click on it.
I thought I might have built it too far from the last one (though I was careful to keep it a bit closer than the average spacing) so I destroyed it, tried again and built it much closer (I can easily see both milestones in the same screen). Same result.
What am I missing?