dotnet/orleans · error · ArgumentNullException

Value cannot be null. (Parameter 'connectionString')

Error message

Value cannot be null. (Parameter 'connectionString')

What it means

Thrown by AzureStorageOperationOptions.SetTableServiceClient(string connectionString) when the connection string is null or whitespace. Internally invoked by the obsolete ConfigureTableServiceClient(string) overload. A blank connection string cannot construct a TableServiceClient, so it is rejected before any Azure call.

Source

Thrown at src/Azure/Shared/Storage/AzureStorageOperationOptions.cs:125

        /// </summary>
        [Obsolete($"Set the {nameof(TableServiceClient)} property directly.")]
        public void ConfigureTableServiceClient(Uri serviceUri, AzureSasCredential azureSasCredential)
        {
            SetTableServiceClient(serviceUri, azureSasCredential);
        }

        /// <summary>
        /// Configures the <see cref="TableServiceClient"/> using an authenticated service URI and a <see cref="TableSharedKeyCredential"/>.
        /// </summary>
        [Obsolete($"Set the {nameof(TableServiceClient)} property directly.")]
        public void ConfigureTableServiceClient(Uri serviceUri, TableSharedKeyCredential sharedKeyCredential)
        {
            SetTableServiceClient(serviceUri, sharedKeyCredential);
        }

        internal void SetTableServiceClient(string connectionString)
        {
            if (string.IsNullOrWhiteSpace(connectionString)) throw new ArgumentNullException(nameof(connectionString));
            _tableServiceClient = null;
            CreateClient = () => Task.FromResult(new TableServiceClient(connectionString, GetTableClientOptions()));
        }

        internal void SetTableServiceClient(Uri serviceUri)
        {
            if (serviceUri is null) throw new ArgumentNullException(nameof(serviceUri));
            _tableServiceClient = null;
            CreateClient = () => Task.FromResult(new TableServiceClient(serviceUri, GetTableClientOptions()));
        }

        internal void SetTableServiceClient(Uri serviceUri, TokenCredential tokenCredential)
        {
            if (serviceUri is null) throw new ArgumentNullException(nameof(serviceUri));
            if (tokenCredential is null) throw new ArgumentNullException(nameof(tokenCredential));
            _tableServiceClient = null;
            CreateClient = () => Task.FromResult(new TableServiceClient(serviceUri, tokenCredential, GetTableClientOptions()));
        }

View on GitHub (pinned to fca799fa70)

Solutions

1. Provide a valid Azure Storage connection string (or, preferred, set TableServiceClient directly).
2. Verify the config key exists and is bound via configuration binding before calling configure.
3. Fail fast at startup with a clear message if the connection string section is absent.

Example fix

// before
options.ConfigureTableServiceClient(config["AzureStorageConnectionString"]); // null if key missing
// after
var cs = config["AzureStorageConnectionString"] ?? throw new InvalidOperationException("Missing AzureStorageConnectionString");
options.TableServiceClient = new TableServiceClient(cs);

var cs = config["AzureStorageConnectionString"];
if (string.IsNullOrWhiteSpace(cs)) throw new InvalidOperationException("Missing AzureStorageConnectionString");
options.TableServiceClient = new TableServiceClient(cs);

static bool HasConnectionString(string? s) => !string.IsNullOrWhiteSpace(s);

catch (ArgumentNullException ex) when (ex.ParamName == "connectionString") { /* verify the config key and secret source */ }

When it happens

Trigger: Calling ConfigureTableServiceClient(connectionString) with a null/empty string, typically because a configuration key (e.g. "AzureStorageConnectionString") was missing from appsettings or environment.

Common situations: Missing or renamed connection-string key in appsettings.json / environment variables; secret not loaded in the deployed environment; local dev using placeholder that resolves to empty.

Related errors

• Value cannot be null. (Parameter 'createClientCallback')
• Value cannot be null. (Parameter 'serviceUri')
• Value cannot be null. (Parameter 'tokenCredential')
• Value cannot be null. (Parameter 'azureSasCredential')
• Value cannot be null. (Parameter 'sharedKeyCredential')

AI-assisted analysis of dotnet/orleans@fca799fa70 (2026-08-13). Data as JSON: /api/errors/3038b94151ce5709. Report an issue: GitHub.