Just want to check that it's not my system: Normally I can view any Garmin Topo Maps on my devices by connecting them to my PC and loading Basecamp. It's a very slow process but does work. I've just downloaded 2 of the latest maps (Hong Kong and also China) and I now get an error saying there is an issue with both the maps. This happens on my D2 Mach 2 Pro and also on my H1 Plus. Loading the maps from SD card doesn't work either. My other maps are all fine and the devices can use the new maps without issue.
I am aware that Garmin don't support Basecamp anymore and that this was bound to happen eventually. Have the map file formats changed recently? If they have I'll stop trying and find alternative maps as I use Basecamp for all my planing as I can't stand the lag and latency of the online Explore site and my fingers are not nimble enough to use the smartphone app!