HangfireIO/Hangfire · error · ArgumentNullException

configuration

Error message

configuration

What it means

SetDataCompatibilityLevel is a fluent extension on IGlobalConfiguration that stores the data-serialization compatibility level. It throws ArgumentNullException(nameof(configuration)) at GlobalConfiguration.cs:61 when the receiver is null, because it must return that same configuration to keep the fluent chain alive.

Source

Thrown at src/Hangfire.Core/GlobalConfiguration.cs:61

        }

        internal static bool HasCompatibilityLevel(CompatibilityLevel level)
        {
            return CompatibilityLevel >= level;
        }

        internal GlobalConfiguration()
        {
        }
    }

    public static class CompatibilityLevelExtensions
    {
        public static IGlobalConfiguration SetDataCompatibilityLevel(
            [NotNull] this IGlobalConfiguration configuration,
            CompatibilityLevel compatibilityLevel)
        {
            if (configuration == null) throw new ArgumentNullException(nameof(configuration));

#if !NETSTANDARD1_3
            if (!Enum.IsDefined(typeof(CompatibilityLevel), compatibilityLevel))
                throw new InvalidEnumArgumentException(nameof(compatibilityLevel), (int) compatibilityLevel,
                    typeof(CompatibilityLevel));
#endif

            GlobalConfiguration.CompatibilityLevel = compatibilityLevel;

            return configuration;
        }
    }
}

View on GitHub (pinned to c236dd0f93)

Solutions

1. Start the fluent chain from GlobalConfiguration.Configuration, which is a never-null singleton (GlobalConfiguration.cs:37).
2. If you hold the config in a field/parameter, null-check it before chaining.
3. When wiring through DI, ensure the factory always returns a non-null IGlobalConfiguration.
4. Build the whole configuration chain in one statement so no intermediate variable can be null.

Example fix

// before
IGlobalConfiguration cfg = null;
cfg.SetDataCompatibilityLevel(CompatibilityLevel.Version_170);
// after
GlobalConfiguration.Configuration
    .SetDataCompatibilityLevel(CompatibilityLevel.Version_170);

// always start from the never-null singleton
GlobalConfiguration.Configuration
    .SetDataCompatibilityLevel(CompatibilityLevel.Version_170);

// or, with a captured variable:
if (configuration == null)
    throw new ArgumentNullException(nameof(configuration));
configuration.SetDataCompatibilityLevel(CompatibilityLevel.Version_170);

static bool IsConfigured(IGlobalConfiguration? c) => c != null;

When it happens

Trigger: Invoking ((IGlobalConfiguration)null).SetDataCompatibilityLevel(CompatibilityLevel.Version_170), or storing the config in a field that is later null and calling .SetDataCompatibilityLevel on it.

Common situations: Not bootstrapping configuration from the singleton GlobalConfiguration.Configuration; assigning the IGlobalConfiguration from a DI factory that can return null; calling UseXxx before the config object is created.

Related errors

• compatibilityLevel
• configuration
• storage
• options
• WorkerCount property value should be positive.

AI-assisted analysis of HangfireIO/Hangfire@c236dd0f93 (2026-08-13). Data as JSON: /api/errors/9780ffd08d95f345. Report an issue: GitHub.