What causes "Configuration is not provided." in microsoft/semantic-kernel?

Recognize this line is effectively dead code; the real validation happens on the next two lines via ArgumentNullException.ThrowIfNull.

microsoft/semantic-kernel · warning · InvalidOperationException

Configuration is not provided.

Error message

Configuration is not provided.

What it means

The null-coalescing throw checks whether ConfigurationBuilder().Build() returns null, then throws InvalidOperationException. In practice, Microsoft.Extensions.Configuration.ConfigurationBuilder.Build() never returns null — it always returns a non-null IConfigurationRoot — making this throw effectively unreachable dead code. The check is defensive but cannot fire under normal library behavior.

Source

Thrown at dotnet/samples/Demos/TimePlugin/Program.cs:16

// Copyright (c) Microsoft. All rights reserved.
#pragma warning disable VSTHRD111 // Use ConfigureAwait(bool)
#pragma warning disable CA1050 // Declare types in namespaces
#pragma warning disable CA2007 // Consider calling ConfigureAwait on the awaited task

using System.ComponentModel;
using Microsoft.Extensions.Configuration;
using Microsoft.SemanticKernel;
using Microsoft.SemanticKernel.ChatCompletion;
using Microsoft.SemanticKernel.Connectors.OpenAI;

var config = new ConfigurationBuilder()
    .AddUserSecrets<Program>()
    .AddEnvironmentVariables()
    .Build()
    ?? throw new InvalidOperationException("Configuration is not provided.");

ArgumentNullException.ThrowIfNull(config["OpenAI:ChatModelId"], "OpenAI:ChatModelId");
ArgumentNullException.ThrowIfNull(config["OpenAI:ApiKey"], "OpenAI:ApiKey");

var kernelBuilder = Kernel.CreateBuilder().AddOpenAIChatCompletion(
    modelId: config["OpenAI:ChatModelId"]!,
    apiKey: config["OpenAI:ApiKey"]!);

kernelBuilder.Plugins.AddFromType<TimeInformationPlugin>();
var kernel = kernelBuilder.Build();

// Get chat completion service
var chatCompletionService = kernel.GetRequiredService<IChatCompletionService>();

// Enable auto function calling
OpenAIPromptExecutionSettings openAIPromptExecutionSettings = new()
{
    FunctionChoiceBehavior = FunctionChoiceBehavior.Auto()

View on GitHub (pinned to c028a0c7dc)

Solutions

Recognize this line is effectively dead code; the real validation happens on the next two lines via ArgumentNullException.ThrowIfNull.
Ensure OpenAI:ChatModelId and OpenAI:ApiKey are set in user secrets or environment variables.
Remove the misleading null-coalescing throw or replace it with a meaningful check on specific keys.
If you encounter this exact message in a stack trace, suspect a custom IConfigurationBuilder or a framework version anomaly — otherwise look at the ArgumentNullException lines below it.

Example fix

// before — unreachable check on Build()
var config = new ConfigurationBuilder()
    .AddUserSecrets<Program>()
    .AddEnvironmentVariables()
    .Build()
    ?? throw new InvalidOperationException("Configuration is not provided.");

// after — Build() never returns null; validate the keys that matter
var config = new ConfigurationBuilder()
    .AddUserSecrets<Program>()
    .AddEnvironmentVariables()
    .Build();

ArgumentNullException.ThrowIfNull(config["OpenAI:ChatModelId"], "OpenAI:ChatModelId");
ArgumentNullException.ThrowIfNull(config["OpenAI:ApiKey"], "OpenAI:ApiKey");

Defensive patterns

Strategy: validation

Validate before calling

// Skip the dead Build() null-check; validate the keys that matter
var modelId = config["OpenAI:ChatModelId"];
var apiKey = config["OpenAI:ApiKey"];
if (string.IsNullOrWhiteSpace(modelId)) throw new ArgumentNullException(nameof(modelId), "Set OpenAI:ChatModelId in user secrets or env.");
if (string.IsNullOrWhiteSpace(apiKey)) throw new ArgumentNullException(nameof(apiKey), "Set OpenAI:ApiKey in user secrets or env.");

Prevention

Don't rely on Build() returning null — it never does in Microsoft.Extensions.Configuration.
Validate specific required keys immediately after Build().
Use user secrets consistently and verify the UserSecretsId in the .csproj.

When it happens

Trigger: This throw is unreachable in practice: Build() returns a non-null IConfigurationRoot even when no providers are configured. It would only fire if a custom IConfigurationBuilder implementation overrode Build() to return null, which is not the case here.

Common situations: Developers see this message and believe configuration is missing, but the real problem is that config keys (OpenAI:ChatModelId, OpenAI:ApiKey) are null — the subsequent ArgumentNullException.ThrowIfNull calls are what actually fire for missing keys, not this line.

Related errors

AI-assisted analysis of microsoft/semantic-kernel@c028a0c7dc (2026-08-13). Data as JSON: /api/errors/11f93389b5d5519f. Report an issue: GitHub.