airbnb/lottie-android · error · JsonDataException

Cannot skip unexpected {} at {}

Error message

Cannot skip unexpected {} at {}

What it means

JsonUtf8Reader.skipName() is called when the parser encounters a property name it doesn't recognize. If the JsonReader's failOnUnknown flag is true (strict mode), instead of skipping it throws JsonDataException, refusing to silently ignore unknown properties. This is a deliberate strict-validation behavior — the library is configured to fail on any unrecognized key in the Lottie JSON.

Source

Thrown at lottie/src/main/java/com/airbnb/lottie/parser/moshi/JsonUtf8Reader.java:578

    // can restore the peek state in case we fail to find a match.
    String lastPathName = pathNames[stackSize - 1];

    String nextName = nextName();
    result = findName(nextName, options);

    if (result == -1) {
      peeked = PEEKED_BUFFERED_NAME;
      peekedString = nextName;
      // We can't push the path further, make it seem like nothing happened.
      pathNames[stackSize - 1] = lastPathName;
    }

    return result;
  }

  @Override public void skipName() throws IOException {
    if (failOnUnknown) {
      throw new JsonDataException("Cannot skip unexpected " + peek() + " at " + getPath());
    }
    int p = peeked;
    if (p == PEEKED_NONE) {
      p = doPeek();
    }
    if (p == PEEKED_UNQUOTED_NAME) {
      skipUnquotedValue();
    } else if (p == PEEKED_DOUBLE_QUOTED_NAME) {
      skipQuotedValue(DOUBLE_QUOTE_OR_SLASH);
    } else if (p == PEEKED_SINGLE_QUOTED_NAME) {
      skipQuotedValue(SINGLE_QUOTE_OR_SLASH);
    } else if (p != PEEKED_BUFFERED_NAME) {
      throw new JsonDataException("Expected a name but was " + peek() + " at path " + getPath());
    }
    peeked = PEEKED_NONE;
    pathNames[stackSize - 1] = "null";
  }

View on GitHub (pinned to 05ea92e903)

Solutions

1. Upgrade the Lottie library to a version that recognizes the property.
2. If you control the animation file, remove the unknown property from the JSON.
3. If strict mode was explicitly enabled, disable failOnUnknown on the reader (note: the standard Lottie parser does not enable this by default).

LottieTask<LottieComposition> task = LottieCompositionFactory.fromAsset(context, name);
task.addListener(result -> { /* success */ })
     .addFailureListener(e -> {
         if (e instanceof JsonDataException && e.getMessage().contains("Cannot skip")) {
             // unknown property in strict mode
         }
     });

When it happens

Trigger: The Lottie JSON contains a property name that this version of the Lottie library does not recognize, AND the JsonReader has been configured with failOnUnknown=true. This could be a newer Lottie spec field, a custom/extension field, or a typo in the JSON.

Common situations: Loading a Lottie animation that uses newer spec fields not supported by the current library version; strict-mode parsing configuration enabled; animation contains custom metadata fields that the parser doesn't expect.

Related errors

• Nesting too deep at {}
• Expected BEGIN_ARRAY but was {} at path {}
• Expected END_ARRAY but was {} at path {}
• Expected BEGIN_OBJECT but was {} at path {}
• Expected END_OBJECT but was {} at path {}

AI-assisted analysis of airbnb/lottie-android@05ea92e903 (2026-08-14). Data as JSON: /api/errors/bd2d089c4e70c6b1. Report an issue: GitHub.