OpenRA/OpenRA · error · InvalidDataException

Map format {format} is not supported.

Error message

Map format {format} is not supported.

What it means

While building a preview, UpdateFromMap reads MapFormat from yaml and rejects maps below Map.SupportedMapFormat (11). Previews of legacy maps are not supported by the current engine.

Source

Thrown at OpenRA.Game/Map/MapPreview.cs:384

			Dictionary<string, MiniYaml> yaml;
			using (var yamlStream = p.GetStream("map.yaml"))
			{
				if (yamlStream == null)
					throw new FileNotFoundException("Required file map.yaml not present in this map");

				yaml = new MiniYaml(null, MiniYaml.FromStream(yamlStream, $"{p.Name}:map.yaml", stringPool: cache.StringPool)).ToDictionary();
			}

			var newData = innerData.Clone();
			newData.Class = classification;
			newData.GridType = gridType ?? modData.GetOrCreate<MapGrid>().Type;

			if (yaml.TryGetValue("MapFormat", out var temp))
			{
				var format = FieldLoader.GetValue<int>("MapFormat", temp.Value);
				if (format < Map.SupportedMapFormat)
					throw new InvalidDataException($"Map format {format} is not supported.");
			}

			if (yaml.TryGetValue("Title", out temp))
				newData.Title = temp.Value;

			if (yaml.TryGetValue("Categories", out temp))
				newData.Categories = FieldLoader.GetValue<ImmutableArray<string>>("Categories", temp.Value);

			if (yaml.TryGetValue("Tileset", out temp))
				newData.TileSet = temp.Value;

			if (yaml.TryGetValue("Author", out temp))
				newData.Author = temp.Value;

			if (yaml.TryGetValue("Bounds", out temp))
				newData.Bounds = FieldLoader.GetValue<Rectangle>("Bounds", temp.Value);

			if (yaml.TryGetValue("Visibility", out temp))

View on GitHub (pinned to a520984d91)

Solutions

1. Migrate the map forward by re-saving in a compatible older release, then current.
2. Remove the legacy map from the scanned folder.
3. Filter the preview list to maps whose format is current.

if (yaml.TryGetValue("MapFormat", out var temp) &&
    FieldLoader.GetValue<int>("MapFormat", temp.Value) < Map.SupportedMapFormat)
    return; // skip legacy map in preview

try { preview.UpdateFromMap(p, classification); }
catch (InvalidDataException e) when (e.Message.Contains("is not supported"))
{ /* skip legacy map */ }

When it happens

Trigger: MapPreview.UpdateFromMap: yaml has MapFormat and format < Map.SupportedMapFormat.

Common situations: A legacy map (format < 11) sitting in the maps folder; previewing a map authored before a format bump.

Related errors

• Map format {MapFormat} is not supported.\n File: {package.Na
• MapFormat is not defined
• Required file map.yaml not present in this map
• Invalid map uid: {uid}
• No valid shellmaps available

AI-assisted analysis of OpenRA/OpenRA@a520984d91 (2026-08-13). Data as JSON: /api/errors/2ec959d79b5f4a11. Report an issue: GitHub.