apache/flink · error · RuntimeException

Unable to deserialize byte array.

Error message

Unable to deserialize byte array.

What it means

Error "Unable to deserialize byte array." thrown in apache/flink.

Source

Thrown at flink-formats/flink-csv/src/main/java/org/apache/flink/formats/csv/RowCsvInputFormat.java:307

                createNullableRuntimeConverter(elementType, ignoreParseErrors);

        return (node) -> {
            final int nodeSize = node.size();
            final Object[] array = (Object[]) Array.newInstance(elementClass, nodeSize);
            for (int i = 0; i < nodeSize; i++) {
                array[i] = elementConverter.convert(node.get(i));
            }
            return array;
        };
    }

    private static RuntimeConverter createByteArrayRuntimeConverter(boolean ignoreParseErrors) {
        return (node) -> {
            try {
                return node.binaryValue();
            } catch (IOException e) {
                if (!ignoreParseErrors) {
                    throw new RuntimeException("Unable to deserialize byte array.", e);
                }
                return null;
            }
        };
    }

    static void validateArity(int expected, int actual, boolean ignoreParseErrors) {
        if (expected != actual && !ignoreParseErrors) {
            throw new RuntimeException(
                    "Row length mismatch. "
                            + expected
                            + " fields expected but was "
                            + actual
                            + ".");
        }
    }

    /** Create a builder. */

View on GitHub (pinned to 2f3c205e92)

Solutions

1. Address the cause reported by the error message: Unable to deserialize byte array.
2. Verify the inputs, configuration values, and classpath/dependency setup related to this operation, then retry.

Example fix

Correct the condition described ("Unable to deserialize byte array.") and rerun the job or command.

When it happens

Trigger: Triggered at runtime when the operation fails because: Unable to deserialize byte array.

Common situations: Commonly caused by misconfiguration, missing dependencies or files, unsupported types or operations, or invalid user input leading to: Unable to deserialize byte array.

AI-assisted analysis of apache/flink@2f3c205e92 (2026-08-14). Data as JSON: /api/errors/342b8387c894cd55. Report an issue: GitHub.