airbnb/lottie-android · error · IllegalArgumentException

Unknown point starts with {}

Error message

Unknown point starts with {}

What it means

JsonUtils.jsonToPoint() parses a 2D point from the JSON stream. It handles three token types: NUMBER (bare x,y pair), BEGIN_ARRAY ([x,y]), and BEGIN_OBJECT ({x:...,y:...}). Any other leading token throws IllegalArgumentException. This fires during Lottie JSON parsing when a point field (vertex, in-tangent, out-tangent, position, anchor point) starts with unexpected JSON structure.

Source

Thrown at lottie/src/main/java/com/airbnb/lottie/parser/JsonUtils.java:55

    while (reader.peek() == JsonReader.Token.BEGIN_ARRAY) {
      reader.beginArray();
      points.add(jsonToPoint(reader, scale));
      reader.endArray();
    }
    reader.endArray();
    return points;
  }

  static PointF jsonToPoint(JsonReader reader, float scale) throws IOException {
    switch (reader.peek()) {
      case NUMBER:
        return jsonNumbersToPoint(reader, scale);
      case BEGIN_ARRAY:
        return jsonArrayToPoint(reader, scale);
      case BEGIN_OBJECT:
        return jsonObjectToPoint(reader, scale);
      default:
        throw new IllegalArgumentException("Unknown point starts with " + reader.peek());
    }
  }

  private static PointF jsonNumbersToPoint(JsonReader reader, float scale) throws IOException {
    float x = (float) reader.nextDouble();
    float y = (float) reader.nextDouble();
    while (reader.hasNext()) {
      reader.skipValue();
    }
    return new PointF(x * scale, y * scale);
  }

  private static PointF jsonArrayToPoint(JsonReader reader, float scale) throws IOException {
    float x;
    float y;
    reader.beginArray();
    x = (float) reader.nextDouble();
    y = (float) reader.nextDouble();

View on GitHub (pinned to 05ea92e903)

Solutions

1. Validate the Lottie JSON with a JSON linter and Lottie validator (e.g., lottiefiles.com validator) before loading.
2. Locate the point field in the JSON where parsing fails (use the path/line info from the exception) and fix the malformed coordinate data.
3. If the file is from a third party, re-download or re-export it to eliminate corruption.

// Pre-validate the JSON is well-formed before loading into Lottie
try (JsonReader reader = JsonReader.of(source)) {
    // quick structural validation pass
} catch (Exception e) {
    // JSON is malformed; do not pass to Lottie
}

LottieTask<LottieComposition> task = LottieCompositionFactory.fromAsset(context, name);
task.addListener(result -> { /* success */ })
     .addFailureListener(e -> { /* malformed JSON — show fallback */ });

When it happens

Trigger: The Lottie JSON contains a point value that is neither a number, an array, nor an object — e.g., a string, boolean, or null where coordinates are expected. Also possible with truncated or corrupted JSON where the reader encounters an unexpected token after a structural error earlier in the stream.

Common situations: Corrupted or truncated Lottie animation file; animation exported by a non-standard tool that formats points differently; hand-edited JSON with syntax errors in coordinate sections.

Related errors

• Cannot convert json to point. Next token is {}
• Unknown value for token of type {}
• Unknown trim path type {}
• Shape data was missing information.
• {} at path {}

AI-assisted analysis of airbnb/lottie-android@05ea92e903 (2026-08-14). Data as JSON: /api/errors/67281938f4a50de0. Report an issue: GitHub.