Hmm, interestingly, the current 1888a YAML is valid.
I think those error message I found might have been older.
So, at this juncture, the ball is in my court for server updates and further investigation of why more maps are not showing up.

Did a quick report on invalid maps, just one with invalid YAML that I found:

Invalid map.yml data found at URI: https://github.com/triplea-maps/1888a_steam_and_steel/blob/master/map.yml?raw=true, error: Invalid yaml format: mapping values are not allowed here

Second, the server needs to be updated to also check for a 'main' branch in the maps. That would fix a few more maps. (We should prefer "main" as our default branch name going forward rather than "master", fwiw. I'm a bit tempted to bulk update all maps to use 'main' as its default branch).

It does seem like there should be quite a few more maps though, even with those fixes applied. I'll need to investigate further to see why/where more maps are not being picked up.

If you tried to download one of these broken maps now, would there be an error.

In those cases the download button would be disabled. So, the map description area would be a place where the server would report the map problems, and no download button.

You may notice, some maps are missing their description.html file, the map download window indicates that file is missing in the description area (but still allows download). So, similar strategy for the maps are fully broken.

The alternative I was thinking was to have a dedicated website page with a big table of each map and its status. That might still be in the cards, but feels cleaner to have that info directly built into the game (and the map tag management I think should be there too rather than in the moderator toolbox).

I notice that there some maps which always a need to download such as Alexander 350BC. the mpa.yml file is

I believe that YAML snippet is fine. The "map_name" is the name of the download, it is the name of the download. After download, the "game name" is the thing that people select as what they want to play, and the "file_name" is a path to the XML file so that the game engine knows where the game data is physically located. FWIW, these values are all now explicit, before the game engine just assumed that the XML had a value that matched the map name, which would match the folder name of the map, etc.. Now none of those need to match, all the "index" information is read from the "map.yml" file. (Of course, to keep compatibility with 2.5 engines, the folder & map names do need to match, with 2.7 the structure and naming is more flexible and less important)

@rogercooper
Checkout this post from LaFayette
https://forums.triplea-game.org/topic/4056/1888a-steam-steel-official-thread/34?page=2

Note the spaces near the { }

map_name: 1888a_steam_and_steel
games:

{ game_name: "1888A Steam and Steel", file_name: 1888a_steam_and_steel.xml }
or:

map_name: 1888a_steam_and_steel
games:

game_name: 1888A Steam and Steel
file_name: 1888a_steam_and_steel.xml

@lafayette If you tried to download one of these broken maps now, would there be an error. Can you give me example of a broken map.

I have already added every finished map to triplea_maps.yaml and downloaded them all without error.

I notice that there some maps which always a need to download such as Alexander 350BC. the mpa.yml file is

map_name: Alexander350 games: - {game_name: 'Alexander350', file_name: Alexander350.xml}

I notice that says game_name, not map_name. Is that the issue?