Unity-Technologies/UnityCsReference · critical · System.Exception

Build platforms are not initialized.

Error message

Build platforms are not initialized.

What it means

Thrown by EditorUserBuildSettingsUtils.CalculateSelectedBuildTarget when BuildPlatforms.instance is null for a non-Standalone build target. The build-platforms subsystem must be initialized before this helper can resolve a NamedBuildTarget to a BuildTarget; querying it too early (during editor boot, before the build window registers platforms) throws.

Source

Thrown at Editor/Mono/EditorUserBuildSettingsUtils.cs:29

        public static BuildTarget CalculateSelectedBuildTarget()
        {
            NamedBuildTarget namedBuildTarget = CalculateSelectedNamedBuildTarget();
            return CalculateSelectedBuildTarget(namedBuildTarget);
        }

        internal static BuildTarget CalculateSelectedBuildTarget(NamedBuildTarget namedBuildTarget)
        {
            if (namedBuildTarget.ToBuildTargetGroup() == BuildTargetGroup.Standalone)
            {
                BuildTarget target = EditorUserBuildSettings.selectedStandaloneTarget;
                if (target == BuildTarget.NoTarget)
                    target = EditorUserBuildSettings.activeBuildTarget;
                return DesktopStandaloneBuildWindowExtension.GetBestStandaloneTarget(target);
            }
            else
            {
                if (BuildPlatforms.instance == null)
                    throw new System.Exception("Build platforms are not initialized.");
                BuildPlatform platform = BuildPlatforms.instance.BuildPlatformFromNamedBuildTarget(namedBuildTarget);
                if (platform == null)
                    throw new System.Exception("Could not find build platform for target group " + namedBuildTarget.TargetName);
                return platform.defaultTarget;
            }
        }

        public static NamedBuildTarget CalculateSelectedNamedBuildTarget()
        {
            BuildTargetGroup targetGroup = EditorUserBuildSettings.selectedBuildTargetGroup;
            if (targetGroup == BuildTargetGroup.Unknown)
                targetGroup = EditorUserBuildSettings.activeBuildTargetGroup;

            // TODO: Eventually NamedBuildTarget will replace completetly BuildTargetGroup, and we won't need this custom check
            if (targetGroup == BuildTargetGroup.Standalone)
            {
                if (EditorUserBuildSettings.selectedStandaloneBuildSubtarget == StandaloneBuildSubtarget.Server)
                    return NamedBuildTarget.Server;

View on GitHub (pinned to 225b0fbdb5)

Solutions

1. Defer the call until after editor initialization (EditorApplication.update callback, deferred once).
2. Restrict to Standalone targets during early init, or short-circuit when BuildPlatforms.instance is null.
3. Guard with a null check on BuildPlatforms.instance and skip/log instead of forcing the call.
4. Move build-target queries out of [InitializeOnLoad] into a delayed initialization path.

Example fix

// before
[InitializeOnLoad]
static class C {
  static C() {
    var t = EditorUserBuildSettingsUtils.CalculateSelectedBuildTarget(namedTarget);
  }
}

// after
[InitializeOnLoad]
static class C {
  static C() {
    EditorApplication.delayCall += () => {
      if (BuildPlatforms.instance != null)
        var t = EditorUserBuildSettingsUtils.CalculateSelectedBuildTarget(namedTarget);
    };
  }
}

if (BuildPlatforms.instance == null) { Debug.LogWarning("Build platforms not ready; deferring"); return BuildTarget.NoTarget; }

static bool AreBuildPlatformsReady => BuildPlatforms.instance != null;

When it happens

Trigger: Calling CalculateSelectedBuildTarget (directly or via build pipeline code) for a non-Standalone NamedBuildTarget during early editor initialization, before BuildPlatforms has been constructed by the build window/editor load sequence.

Common situations: An editor startup script or [InitializeOnLoad] method that queries the selected build target before the build subsystem is ready; headless editor runs where the build window was never opened; package code that calls build settings helpers at static-constructor time.

Related errors

• Could not find build platform for target group ${namedBuildT
• Could not map typename 'GameManager' to type info (initializ
• No valid types in required type list
• Parameter selected must be of type System.Enum
• Parameter enumValue must be of type System.Enum

AI-assisted analysis of Unity-Technologies/UnityCsReference@225b0fbdb5 (2026-08-13). Data as JSON: /api/errors/6a0fd6ec2a8d1492. Report an issue: GitHub.