So, I've been travelling around the world a lot over the last couple of months, and one thing that I've been doing to avoid big roaming data charges on my personal phone, has been using the cached offline maps feature in Google Maps. This has worked without any problems in China, Australia, the UK and the US.
So I'm now in Brazil, and I suddenly find that I can't download any offline maps of the local areas.
When I go to the menu in Google Maps and select Make Available Offline, I get the usual square overlay to select the area, and then it turns red and says "Offline maps is not available in selected area".
I've tried zooming in and out, and moving the selection area around, but no luck.