JamesNK/Newtonsoft.Json · error · JsonException

Unexpected character while parsing path indexer:

Error message

Unexpected character while parsing path indexer: 

What it means

Thrown by the JPath array-indexer parser when a wildcard '*' is followed by a character other than the indexer's closing bracket. After consuming '*' and whitespace, the parser expects ']' (or ')'); anything else (JPath.cs:331-333) is rejected.

Source

Thrown at Src/Newtonsoft.Json/Linq/JsonPath/JPath.cs:333

                    string indexer = _expression.Substring(start, length);
                    indexes.Add(Convert.ToInt32(indexer, CultureInfo.InvariantCulture));

                    _currentIndex++;

                    EatWhitespace();

                    start = _currentIndex;
                    end = null;
                }
                else if (currentCharacter == '*')
                {
                    _currentIndex++;
                    EnsureLength("Path ended with open indexer.");
                    EatWhitespace();

                    if (_expression[_currentIndex] != indexerCloseChar)
                    {
                        throw new JsonException("Unexpected character while parsing path indexer: " + currentCharacter);
                    }

                    return new ArrayIndexFilter();
                }
                else if (currentCharacter == ':')
                {
                    int length = (end ?? _currentIndex) - start;

                    if (length > 0)
                    {
                        string indexer = _expression.Substring(start, length);
                        int index = Convert.ToInt32(indexer, CultureInfo.InvariantCulture);

                        if (colonCount == 0)
                        {
                            startIndex = index;
                        }
                        else if (colonCount == 1)

View on GitHub (pinned to 4f73e74372)

Solutions

1. Use '[*]' alone for a wildcard, or '[0]' for a specific index, never both in one indexer.
2. Remove any trailing characters after '*' inside the brackets.
3. If you need multiple indices, use a comma list of integers: $[0,1].

Example fix

// before
token.SelectToken("$[*1]");

// after
token.SelectToken("$[*]");

// Use '*' only as a standalone wildcard, never mixed with indices
string indexer = wantAll ? "[*]" : $"[{index}]";
string path = $"$.data{indexer}";

When it happens

Trigger: A path like token.SelectToken("$[*1]") or "$[*,0]" where '*' is not immediately followed by the closing ']'. The parser advances past '*' then finds an unexpected character.

Common situations: Mixing wildcard and explicit index syntax; typos where '*' is meant as multiplication or a glob; concatenation placing extra content inside a wildcard indexer.

Related errors

• Array index expected.
• Index * not valid on {0}.
• Unexpected character while parsing path:
• Unexpected character following indexer:
• Unexpected end while parsing path.

AI-assisted analysis of JamesNK/Newtonsoft.Json@4f73e74372 (2026-08-07). Data as JSON: /api/errors/65712d14bd0dd369. Report an issue: GitHub.