stride3d/stride · error · InvalidOperationException

Could not find package

Error message

Could not find package {packageInfo.Name} {packageInfo.Version}. Ensure packages have been resolved.

What it means

StrideDefaultTemplates.Load resolves the built-in template packages (Stride.Assets.Presentation and Stride.SpriteStudio.Offline) at exactly StrideVersion.NuGetVersion via PackageStore; if GetPackageFileName returns null the package was never downloaded/resolved into the store, so it throws InvalidOperationException.

Solutions

Restore the Stride NuGet packages (open the launcher/Game Studio to trigger download, or `dotnet restore` on a project referencing them) for the exact StrideVersion.
Check network/proxy/NuGet source configuration so packages can be fetched.
Verify the package cache (%USERPROFILE%\.nuget\packages\stride.assets.presentation) contains the expected version; reinstall Stride if not.
Ensure the editor version and StrideVersion.NuGetVersion agree; downgrade/upgrade to matching versions.

Example fix

// before: offline machine, store empty
// after
dotnet nuget add source https://api.nuget.org/v3/index.json
dotnet restore MyGame.csproj // pulls stride.assets.presentation <version>

Defensive patterns

Strategy: try-catch

Validate before calling

var pkg = PackageStore.Instance.GetPackageFileName(
    "Stride.Assets.Presentation",
    new PackageVersionRange(new PackageVersion(StrideVersion.NuGetVersion)));
if (pkg is null)
    throw new InvalidOperationException($"Restore stride.assets.presentation {StrideVersion.NuGetVersion} first.");

Try / catch

try
{
    StrideDefaultTemplates.Load(session, logger);
}
catch (InvalidOperationException ex) when (ex.Message.Contains("Could not find package"))
{
    logger.Error($"Run package restore / check NuGet sources: {ex.Message}");
}

Prevention

Ensure NuGet.org (or your feed) is reachable and configured before using templates
Keep the Stride editor and package versions aligned
Pre-warm the package cache on build agents used for template generation

When it happens

Trigger: Creating a new project/template while the NuGet packages cache does not contain the two required packages at the current Stride version — e.g. offline install, blocked network, or version skew between the editor and restored packages.

Common situations: Corporate proxy/NuGet feed blocked; installed Stride via source build without running package restore; NuGet global-packages folder cleaned; version mismatch after upgrading the editor.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/c9ec4dd5d4f9fe1d. Report an issue: GitHub.

Appendix: source

Thrown at sources/engine/Stride.Assets/Templates/StrideDefaultTemplates.cs:36

public static class StrideDefaultTemplates
{
    /// <summary>
    /// Loads default templates. Pass <paramref name="loadAssemblyReferences"/>=false in headless
    /// test runners so the .sdpkg's referenced assemblies (Stride.Particles etc.) don't get loaded
    /// from .nuget cache — a later sample regen loads them from the sample's bin/ via a different
    /// path, producing duplicate Assembly objects and a DataContract alias conflict at runtime.
    /// </summary>
    public static void Load(bool loadAssemblyReferences = true)
    {
        // Only TemplateFolders are needed here (loaded regardless of this flag); skip the package's
        // assets — they're unused for template registration and slow to load.
        var loadParams = new PackageLoadParameters { LoadAssemblyReferences = loadAssemblyReferences, AutoLoadTemporaryAssets = false };
        foreach (var packageInfo in new[] { new { Name = "Stride.Assets.Presentation", Version = StrideVersion.NuGetVersion }, new { Name = "Stride.SpriteStudio.Offline", Version = StrideVersion.NuGetVersion } })
        {
            var logger = new LoggerResult();
            var packageFile = PackageStore.Instance.GetPackageFileName(packageInfo.Name, new PackageVersionRange(new PackageVersion(packageInfo.Version)));
            if (packageFile is null)
                throw new InvalidOperationException($"Could not find package {packageInfo.Name} {packageInfo.Version}. Ensure packages have been resolved.");
            var package = Package.Load(logger, packageFile.ToOSPath(), loadParams);
            if (logger.HasErrors)
                throw new InvalidOperationException($"Could not load package {packageInfo.Name}:{Environment.NewLine}{logger.ToText()}");

            TemplateManager.RegisterPackage(package);
        }

        DotNetNewTemplateBridge.RegisterProjectTemplates();
    }
}

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