dotnet/aspnetcore · error · InvalidOperationException

Cannot provide a value for property '{propertyName}' on type

Error message

Cannot provide a value for property '{propertyName}' on type '{type.FullName}'. The service provider does not implement '{nameof(IKeyedServiceProvider)}' and therefore cannot provide keyed services.

What it means

Thrown by DefaultComponentPropertyActivator when a component property is decorated with [Inject(Key = someKey)] (requesting a keyed service) but the active IServiceProvider does not implement IKeyedServiceProvider. Blazor's default property injection calls GetService, but keyed injection requires a provider that supports GetKeyedService (added in .NET 8). The check is at DefaultComponentPropertyActivator.cs:79-87.

Source

Thrown at src/Components/Components/src/DefaultComponentPropertyActivator.cs:83

        {
            return static (_, _) => { };
        }

        return Initialize;

        // Return an action whose closure can write all the injected properties
        // without any further reflection calls (just typecasts)
        void Initialize(IServiceProvider serviceProvider, IComponent component)
        {
            foreach (var (propertyName, propertyType, setter, serviceKey) in injectables)
            {
                object? serviceInstance;

                if (serviceKey is not null)
                {
                    if (serviceProvider is not IKeyedServiceProvider keyedServiceProvider)
                    {
                        throw new InvalidOperationException($"Cannot provide a value for property " +
                            $"'{propertyName}' on type '{type.FullName}'. The service provider " +
                            $"does not implement '{nameof(IKeyedServiceProvider)}' and therefore " +
                            $"cannot provide keyed services.");
                    }

                    serviceInstance = keyedServiceProvider.GetKeyedService(propertyType, serviceKey)
                        ?? throw new InvalidOperationException($"Cannot provide a value for property " +
                        $"'{propertyName}' on type '{type.FullName}'. There is no " +
                        $"registered keyed service of type '{propertyType}' with key '{serviceKey}'.");
                }
                else
                {
                    serviceInstance = serviceProvider.GetService(propertyType)
                        ?? throw new InvalidOperationException($"Cannot provide a value for property " +
                        $"'{propertyName}' on type '{type.FullName}'. There is no " +
                        $"registered service of type '{propertyType}'.");
                }

View on GitHub (pinned to 294cab2f9b)

Solutions

1. Ensure the application uses the default Microsoft.Extensions.DependencyInjection ServiceProvider which supports keyed services (.NET 8+).
2. If using a custom IServiceProvider, wrap it so it implements IKeyedServiceProvider.
3. If keyed services are unavailable, switch the [Inject] to a non-keyed registration.

Example fix

// before
[Inject(Key = "primary")] public IMyService Svc { get; set; }
// host: services.AddSingleton(typeof(IMyService), defaultImpl); // no key, provider lacks keyed support

// after — register as keyed and ensure default ServiceProvider
services.AddKeyedSingleton<IMyService>("primary", (sp, k) => new PrimaryImpl());

if (serviceKey is not null && serviceProvider is not IKeyedServiceProvider)
    throw new InvalidOperationException("Provider does not support keyed services.");

static bool SupportsKeyedServices(IServiceProvider sp) => sp is IKeyedServiceProvider;

When it happens

Trigger: Using [Inject(Key = "myKey")] on a Blazor component property when the DI container does not support keyed services (e.g., a custom IServiceProvider, an older hosting setup, or a test harness with a plain ServiceProvider).

Common situations: Using keyed services in a Blazor component but the host's service provider isn't the built-in DI container that supports keys; running component unit tests with a minimal service provider; misconfiguring the host provider factory.

Related errors

• Cannot provide a value for property '{propertyName}' on type
• Cannot provide a value for property '{propertyName}' on type
• Cannot notify about changes because the {GetType()} is confi
• The component activator returned a null value for a componen
• The type {componentType.FullName} does not implement {nameof

AI-assisted analysis of dotnet/aspnetcore@294cab2f9b (2026-08-06). Data as JSON: /api/errors/5ba4b29e8f7a9da7. Report an issue: GitHub.