clockworklabs/SpacetimeDB · error · ArgumentException

Must be 16 bytes

Error message

Must be 16 bytes

What it means

Error "Must be 16 bytes" thrown in clockworklabs/SpacetimeDB.

Source

Thrown at crates/bindings-csharp/BSATN.Runtime/BSATN/Uuid.cs:55

    /// 16 random bytes used for entropy.
    /// </param>
    /// <example>
    /// <code>
    /// var randomBytes = new byte[16];
    /// RandomNumberGenerator.Fill(randomBytes);
    /// var uuid = Uuid.FromRandomBytesV4(randomBytes);
    /// Console.WriteLine(uuid);
    /// // Output: 166a036f-90f3-714a-9731-c8814b70e326
    /// </code>
    /// </example>
    /// <exception cref="ArgumentException">
    /// Thrown if <paramref name="randomBytes"/> is not exactly 16 bytes long.
    /// </exception>
    public static Uuid FromRandomBytesV4(ReadOnlySpan<byte> randomBytes)
    {
        if (randomBytes.Length != 16)
        {
            throw new ArgumentException("Must be 16 bytes", nameof(randomBytes));
        }

        Span<byte> bytes = stackalloc byte[16];
        randomBytes.CopyTo(bytes);
        bytes[6] = (byte)((bytes[6] & 0x0F) | 0x40); // version 4
        bytes[8] = (byte)((bytes[8] & 0x3F) | 0x80); // variant RFC 4122

        return new(U128.FromBytesBigEndian(bytes));
    }

    /// <summary>
    /// Generate a <see cref="Uuid"/> `v7` using a monotonic counter from 0 to 2^31-1,
    /// a Unix timestamp in milliseconds, and 4 random bytes.
    ///
    /// <example>
    /// <code>
    /// int counter = 1;
    /// var now = new Timestamp(1_686_000_000_000);

View on GitHub (pinned to 524b4487d9)

When it happens

Trigger: Thrown at crates/bindings-csharp/BSATN.Runtime/BSATN/Uuid.cs:55 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of clockworklabs/SpacetimeDB@524b4487d9 (2026-08-16). Data as JSON: /api/errors/9921d14caa50cab3. Report an issue: GitHub.