hyperledger/fabric · error

could not unmarshal state for key %s

Error message

could not unmarshal state for key %s

What it means

Returned by Serializer.DeserializeField when the raw value stored under a fields key cannot be proto-unmarshaled into StateData. Corrupt or version-mismatched state for that field is the cause; the state read itself succeeded.

Source

Thrown at core/chaincode/lifecycle/serializer.go:410

	err = proto.Unmarshal(metadataBin, metadata)
	if err != nil {
		return nil, false, errors.Wrapf(err, "could not unmarshal metadata for namespace %s/%s", namespace, name)
	}

	return metadata, true, nil
}

func (s *Serializer) DeserializeField(namespace, name, field string, state ReadableState) (*lb.StateData, error) {
	keyName := FieldKey(namespace, name, field)
	value, err := state.GetState(keyName)
	if err != nil {
		return nil, errors.WithMessagef(err, "could not get state for key %s", keyName)
	}

	stateData := &lb.StateData{}
	err = proto.Unmarshal(value, stateData)
	if err != nil {
		return nil, errors.Wrapf(err, "could not unmarshal state for key %s", keyName)
	}

	return stateData, nil
}

func (s *Serializer) DeserializeFieldAsString(namespace, name, field string, state ReadableState) (string, error) {
	value, err := s.DeserializeField(namespace, name, field, state)
	if err != nil {
		return "", err
	}
	if value.Type == nil {
		return "", nil
	}
	oneOf, ok := value.Type.(*lb.StateData_String_)
	if !ok {
		return "", errors.Errorf("expected key %s/fields/%s/%s to encode a value of type String, but was %T", namespace, name, field, value.Type)
	}
	return oneOf.String_, nil

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Check the wrapped error for the decode failure
2. Overwrite the corrupted field key by re-approving/committing the chaincode definition

When it happens

Trigger: Thrown at core/chaincode/lifecycle/serializer.go:410 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/7c23ac9b977f81b0. Report an issue: GitHub.