Unity-Technologies/UnityCsReference · error · ArgumentException

Platform name '{0}' not supported. Supported platform names:

Error message

Platform name '{0}' not supported.
Supported platform names:
{1}

What it means

Thrown by CustomScriptAssembly.GetPlatformFromName (CustomScriptAssembly.cs:696, ArgumentException) when none of the entries in the static Platforms list match the requested platform name (case-insensitive). The message lists every supported platform name so the developer can pick a valid one. This is reached when resolving names from an asmdef's include/excludePlatforms arrays that were not already rejected as deprecated or renamed.

Source

Thrown at Editor/Mono/Scripting/ScriptCompilation/CustomScriptAssembly.cs:696

            foreach(var platformName in RenamedPlatforms)
                if (string.Equals(platformName, name, System.StringComparison.OrdinalIgnoreCase))
                    return true;

            return false;
        }

        public static CustomScriptAssemblyPlatform GetPlatformFromName(string name)
        {
            foreach (var platform in Platforms)
                if (string.Equals(platform.Name, name, System.StringComparison.OrdinalIgnoreCase))
                    return platform;

            var platformNames = Platforms.ConvertAll(p => string.Format("\"{0}\"", p.Name));
            platformNames.Sort();

            var platformsString = string.Join(",\n", platformNames);

            throw new System.ArgumentException(string.Format("Platform name '{0}' not supported.\nSupported platform names:\n{1}\n", name, platformsString));
        }

        public static CustomScriptAssemblyPlatform GetPlatformFromBuildTarget(BuildTarget buildTarget)
        {
            foreach (var platform in Platforms)
                if (platform.BuildTarget == buildTarget)
                    return platform;

            throw new System.ArgumentException(string.Format("No CustomScriptAssemblyPlatform setup for BuildTarget '{0}'", buildTarget));
        }

        public override bool Equals(object obj)
        {
            if (ReferenceEquals(null, obj)) return false;
            if (ReferenceEquals(this, obj)) return true;
            if (obj.GetType() != this.GetType()) return false;
            return Equals((CustomScriptAssembly) obj);
        }

View on GitHub (pinned to 225b0fbdb5)

Solutions

1. Read the supported platform names printed in the error message and replace the invalid entry with the exact string shown (matching is case-insensitive but the spelling must match).
2. If the platform was renamed, check RenamedPlatforms / DeprecatedPlatforms handling and use the current canonical name (e.g. "iPhone" -> "iOS").
3. If the platform module is genuinely absent from your editor install, install the platform module or remove the entry.

Example fix

// before (.asmdef)
"includePlatforms": ["iPhone"]
// after
"includePlatforms": ["iOS"]

// Validate platform names against the editor's supported set before writing an asmdef
var supported = new HashSet<string>(
    UnityEditor.Compilation.CompilationPipeline.GetAssemblyDefinitionPlatforms()
        .Select(p => p.Name), StringComparer.OrdinalIgnoreCase);

foreach (var p in (data.includePlatforms ?? Array.Empty<string>()).Concat(data.excludePlatforms ?? Array.Empty<string>()))
    if (!supported.Contains(p))
        throw new InvalidOperationException($"Unsupported platform name '{p}'. Valid: {string.Join(", ", supported.OrderBy(x => x))}");

When it happens

Trigger: An asmdef lists a platform name that is not recognized by the installed editor build, e.g. "iPhone" (legacy) after Unity renamed it, or "WebGL" spelled "Webgl", or a platform whose module is not installed.

Common situations: Upgrading a project across Unity versions where a platform was renamed or removed. Sharing an asmdef authored on an editor build that includes a platform the current install lacks. Old tutorials using obsolete platform identifiers.

Related errors

• Both 'excludePlatforms' and 'includePlatforms' are set.
• Invalid Define Constraint: "{DefineConstraints[i]}" at line
• Assembly has duplicate references: {duplicateRefsString}
• Folder '{loadedCustomScriptAssemblyReference.PathPrefix}' co
• Assembly cannot be have reserved name '{loadedCustomScriptAs

AI-assisted analysis of Unity-Technologies/UnityCsReference@225b0fbdb5 (2026-08-13). Data as JSON: /api/errors/b9b77a16b49966fa. Report an issue: GitHub.