JamesNK/Newtonsoft.Json · error · ArgumentException

Value must be positive.

Error message

Value must be positive.

What it means

Thrown by the JsonSerializer.MaxDepth setter when assigning a value less than or equal to zero. MaxDepth bounds JSON nesting depth to prevent stack overflows and denial-of-service via pathological/deeply-nested input; a non-positive bound is invalid, so the setter rejects it with ArgumentException. Null means no limit and is allowed.

Source

Thrown at Src/Newtonsoft.Json/JsonSerializer.cs:528

        public virtual CultureInfo Culture
        {
            get => _culture ?? JsonSerializerSettings.DefaultCulture;
            set => _culture = value;
        }

        /// <summary>
        /// Gets or sets the maximum depth allowed when reading JSON. Reading past this depth will throw a <see cref="JsonReaderException"/>.
        /// A null value means there is no maximum.
        /// The default value is <c>64</c>.
        /// </summary>
        public virtual int? MaxDepth
        {
            get => _maxDepth;
            set
            {
                if (value <= 0)
                {
                    throw new ArgumentException("Value must be positive.", nameof(value));
                }

                _maxDepth = value;
                _maxDepthSet = true;
            }
        }

        /// <summary>
        /// Gets a value indicating whether there will be a check for additional JSON content after deserializing an object.
        /// The default value is <c>false</c>.
        /// </summary>
        /// <value>
        /// 	<c>true</c> if there will be a check for additional JSON content after deserializing an object; otherwise, <c>false</c>.
        /// </value>
        public virtual bool CheckAdditionalContent
        {
            get => _checkAdditionalContent ?? JsonSerializerSettings.DefaultCheckAdditionalContent;
            set => _checkAdditionalContent = value;

View on GitHub (pinned to 4f73e74372)

Solutions

1. Assign a positive integer (64 is the library default).
2. Pass null to explicitly disable the cap.
3. Validate first: if (depth is int d && d > 0) serializer.MaxDepth = d;.

Example fix

// before
serializer.MaxDepth = 0;

// after
serializer.MaxDepth = 64; // or null for no limit

if (configuredDepth is int d && d > 0)
{
    serializer.MaxDepth = d;
}

static bool IsValidMaxDepth(int? v) => v is null or > 0;

When it happens

Trigger: Setting serializer.MaxDepth = 0 or a negative number; feeding MaxDepth from unvalidated config or arithmetic that can go non-positive.

Common situations: Reading MaxDepth from appsettings/environment without bounds checking; passing 0 intending 'default'; subtractive arithmetic producing negatives.

Related errors

• Value must be positive.
• Value must be positive.
• Indentation value must be greater than 0.
• value
• value

AI-assisted analysis of JamesNK/Newtonsoft.Json@4f73e74372 (2026-08-07). Data as JSON: /api/errors/2a54cddfc589bbaf. Report an issue: GitHub.