apache/flink · error · IllegalArgumentException

Field ID must not be null.

Error message

Field ID must not be null.

What it means

Error "Field ID must not be null." thrown in apache/flink.

Source

Thrown at flink-core/src/main/java/org/apache/flink/api/common/operators/util/FieldList.java:60

    public FieldList(Integer fieldId) {
        super(Collections.singletonList(checkNotNull(fieldId, "The fields ID must not be null.")));
    }

    public FieldList(int... columnIndexes) {
        super(fromInts(columnIndexes));
    }

    private FieldList(List<Integer> fields) {
        super(fields);
    }

    // --------------------------------------------------------------------------------------------

    @Override
    public FieldList addField(Integer fieldID) {
        if (fieldID == null) {
            throw new IllegalArgumentException("Field ID must not be null.");
        }

        if (size() == 0) {
            return new FieldList(fieldID);
        } else {
            ArrayList<Integer> list = new ArrayList<Integer>(size() + 1);
            list.addAll(this.collection);
            list.add(fieldID);
            return new FieldList(Collections.unmodifiableList(list));
        }
    }

    @Override
    public FieldList addFields(int... fieldIDs) {
        if (fieldIDs == null || fieldIDs.length == 0) {
            return this;
        }
        if (size() == 0) {

View on GitHub (pinned to 2f3c205e92)

Solutions

1. Address the cause reported by the error message: Field ID must not be null.
2. Verify the inputs, configuration values, and classpath/dependency setup related to this operation, then retry.

Example fix

Correct the condition described ("Field ID must not be null.") and rerun the job or command.

When it happens

Trigger: Triggered at runtime when the operation fails because: Field ID must not be null.

Common situations: Commonly caused by misconfiguration, missing dependencies or files, unsupported types or operations, or invalid user input leading to: Field ID must not be null.

AI-assisted analysis of apache/flink@2f3c205e92 (2026-08-14). Data as JSON: /api/errors/910da956d0d84e00. Report an issue: GitHub.