stride3d/stride · error · InvalidOperationException

Cannot register new platforms. RegisterSupportedPlatforms…

Error message

Cannot register new platforms. RegisterSupportedPlatforms can only be called once

What it means

AssetRegistry.RegisterSupportedPlatforms throws InvalidOperationException if SupportedPlatforms has already been populated. Platform support is a process-wide, write-once static configuration: mixing registration calls would produce ambiguous platform sets.

Solutions

Guard the call: only register when AssetRegistry.SupportedPlatforms.Count == 0.
Move registration to a single central bootstrap point and have other modules read the existing value.
In tests, register once in a one-time setup (or check the guard before each registration).

Example fix

// before
AssetRegistry.RegisterSupportedPlatforms(platforms);
// after
if (AssetRegistry.SupportedPlatforms.Count == 0)
    AssetRegistry.RegisterSupportedPlatforms(platforms);

Defensive patterns

Strategy: validation

Validate before calling

if (AssetRegistry.SupportedPlatforms.Count > 0) return; // already registered
AssetRegistry.RegisterSupportedPlatforms(platforms);

Try / catch

try { AssetRegistry.RegisterSupportedPlatforms(platforms); } catch (InvalidOperationException) { /* already registered - ignore */ }

Prevention

Register platforms exactly once in a single bootstrap method.
Use a Lazy<T>/Singleton for asset-system initialization.
In tests, register in [OneTimeSetUp]/static setup, not per-test.

When it happens

Trigger: Calling AssetRegistry.RegisterSupportedPlatforms a second time in the same process, e.g. from both a plugin and the host app, or in a repeated test setup without clearing state.

Common situations: Two modules each initializing the asset system at startup; unit tests re-registering platforms per fixture because static state persists between tests.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/3cdfcb940c9e7636. Report an issue: GitHub.

Appendix: source

Thrown at sources/assets/Stride.Core.Assets/AssetRegistry.cs:76

    /// </summary>
    /// <value>The supported platforms.</value>
    public static SolutionPlatformCollection SupportedPlatforms { get; }

    /// <summary>
    /// Gets an enumeration of registered importers.
    /// </summary>
    /// <value>The registered importers.</value>
    public static IEnumerable<IAssetImporter> RegisteredImporters { get { lock (RegistryLock) { return RegisteredImportersInternal; } } }

    /// <summary>
    /// Registers the supported platforms.
    /// </summary>
    /// <param name="platforms">The platforms.</param>
    /// <exception cref="System.ArgumentNullException">platforms</exception>
    public static void RegisterSupportedPlatforms(List<SolutionPlatform> platforms)
    {
        ArgumentNullException.ThrowIfNull(platforms);
        if (SupportedPlatforms.Count > 0) throw new InvalidOperationException("Cannot register new platforms. RegisterSupportedPlatforms can only be called once");
        SupportedPlatforms.AddRange(platforms);
    }

    /// <summary>
    /// Determines whether the file is an asset file type.
    /// </summary>
    /// <param name="extension">The file.</param>
    /// <returns><c>true</c> if [is asset file file] [the specified file]; otherwise, <c>false</c>.</returns>
    public static bool IsAssetFileExtension(string? extension)
    {
        if (extension == null) return false;
        lock (RegistryLock)
        {
            return RegisteredAssetFileExtensions.ContainsKey(extension);
        }
    }

    /// <summary>

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