OrchardCMS/OrchardCore · error · ArgumentException

MessageId can't be empty.

Error message

MessageId can't be empty.

What it means

CultureDictionaryRecord.GetKey builds the composite record key from a messageId and optional context, and requires a non-empty messageId. An empty or null messageId would produce a meaningless key, so ArgumentException with the parameter name is thrown as a standard argument guard.

Solutions

1. Ensure the messageId passed to GetKey/record construction is non-empty before calling.
2. Add a guard in your own code (ArgumentException.ThrowIfNullOrWhiteSpace) with a clearer message.
3. Fix the data source producing empty message ids (e.g. skip blank PO entries during import).

Example fix

// before
var key = CultureDictionaryRecord.GetKey(messageId, context);
// after
if (string.IsNullOrWhiteSpace(messageId)) throw new ArgumentException("Message id required", nameof(messageId));
var key = CultureDictionaryRecord.GetKey(messageId, context);

if (string.IsNullOrWhiteSpace(messageId)) return null; // or throw with context
var key = CultureDictionaryRecord.GetKey(messageId, context);

try { key = CultureDictionaryRecord.GetKey(messageId, ctx); }
catch (ArgumentException) { logger.LogWarning("Empty messageId for context '{Context}'; skipping", ctx); }

When it happens

Trigger: Calling GetKey (or the CultureDictionaryRecord constructor that delegates to it) with null, empty, or whitespace messageId — e.g. localizing a string variable that is empty at runtime.

Common situations: Building localization records from parsed PO entries where an entry is malformed, or passing user/editor-supplied text that ends up empty into translation lookup helpers.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

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AI-assisted analysis of OrchardCMS/OrchardCore@4306c0717f (2026-09-13). Data as JSON: /api/errors/c78c78f7844f0cd9. Report an issue: GitHub.

Appendix: source

Thrown at src/OrchardCore/OrchardCore.Localization.Abstractions/CultureDictionaryRecord.cs:51

    /// </summary>
    public CultureDictionaryRecordKey Key { get; }

    /// <summary>
    /// Gets the translation values.
    /// </summary>
    public string[] Translations { get; }

    /// <summary>
    /// Retrieved the resource key using <paramref name="messageId"/> and <paramref name="context"/>.
    /// </summary>
    /// <param name="messageId">The message Id.</param>
    /// <param name="context">The message context.</param>
    /// <returns>The resource key.</returns>
    public static CultureDictionaryRecordKey GetKey(string messageId, string context)
    {
        if (string.IsNullOrEmpty(messageId))
        {
            throw new ArgumentException("MessageId can't be empty.", nameof(messageId));
        }

        return new CultureDictionaryRecordKey
        {
            MessageId = messageId,
            Context = context,
        };
    }
}

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