hyperledger/fabric · error

error unmarshalling Transaction

Error message

error unmarshalling Transaction

What it means

Wrapper error from GetBytesTransaction: the final proto.Marshal(tx) returned an error (note the copy-pasted message says 'unmarshalling' although this is a marshal path). It means Transaction bytes could not be produced for some reason other than the explicit nil guard, or it wraps the nil-marshal failure.

Source

Thrown at protoutil/proputils.go:204

	return bytes, errors.Wrap(err, "error marshaling Header")
}

// GetBytesSignatureHeader get the bytes of SignatureHeader from the message
func GetBytesSignatureHeader(hdr *common.SignatureHeader) ([]byte, error) {
	if hdr == nil {
		return nil, errors.New("error marshaling SignatureHeader: proto: Marshal called with nil")
	}
	bytes, err := proto.Marshal(hdr)
	return bytes, errors.Wrap(err, "error marshaling SignatureHeader")
}

// GetBytesTransaction get the bytes of Transaction from the message
func GetBytesTransaction(tx *peer.Transaction) ([]byte, error) {
	if tx == nil {
		return nil, errors.New("error marshaling Transaction: proto: Marshal called with nil")
	}
	bytes, err := proto.Marshal(tx)
	return bytes, errors.Wrap(err, "error unmarshalling Transaction")
}

// GetBytesPayload get the bytes of Payload from the message
func GetBytesPayload(payl *common.Payload) ([]byte, error) {
	if payl == nil {
		return nil, errors.New("error marshaling Payload: proto: Marshal called with nil")
	}
	bytes, err := proto.Marshal(payl)
	return bytes, errors.Wrap(err, "error marshaling Payload")
}

// GetBytesEnvelope get the bytes of Envelope from the message
func GetBytesEnvelope(env *common.Envelope) ([]byte, error) {
	if env == nil {
		return nil, errors.New("error marshaling Envelope: proto: Marshal called with nil")
	}
	bytes, err := proto.Marshal(env)
	return bytes, errors.Wrap(err, "error marshaling Envelope")

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Read the wrapped cause from the error chain to identify the real marshal failure
2. Ensure all TransactionActions were successfully created from ProposalResponses before marshaling
3. Fix upstream error handling so failures are surfaced before serialization

Example fix

// before
bytes, err := proto.Marshal(tx)
return bytes, errors.Wrap(err, "error unmarshalling Transaction") // misleading label
// after
bytes, err := proto.Marshal(tx)
return bytes, errors.Wrap(err, "error marshaling Transaction")

if tx == nil || len(tx.Actions) == 0 {
	return errors.New("invalid transaction: nil or no actions")
}

func isSerializableTransaction(tx *peer.Transaction) bool {
	return tx != nil && len(tx.Actions) > 0
}

bytes, err := protoutil.GetBytesTransaction(tx)
if err != nil {
	return nil, fmt.Errorf("GetBytesTransaction failed: %w", err)
}

When it happens

Trigger: proto.Marshal(tx) failing inside GetBytesTransaction for callers createSignedTxTwoActions, prepareTransaction, CreateSignedTx; typically a nil or invalid Transaction reaching the marshal call.

Common situations: Fabric SDK/test transaction assembly where an earlier step (GetPayloads, proposal response merging) failed but its error was ignored, leaving an unusable Transaction.

Related errors

• error marshaling SignatureHeader
• error marshaling Payload
• error marshaling Envelope
• error marshaling
• unmarshal failed

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/e80e3cfa38154de4. Report an issue: GitHub.