hyperledger/fabric · error

error unmarshalling ProposalResponsePayload

Error message

error unmarshalling ProposalResponsePayload

What it means

Returned by protoutil.UnmarshalProposalResponsePayload when proto.Unmarshal cannot decode bytes into a peer.ProposalResponsePayload. The wrapper adds message-type context to the protobuf error. It means the payload bytes (proposal hash + extension) are not a valid ProposalResponsePayload encoding.

Source

Thrown at protoutil/unmarshalers.go:144

// UnmarshalResponse unmarshals bytes to a Response
func UnmarshalResponse(resBytes []byte) (*peer.Response, error) {
	response := &peer.Response{}
	err := proto.Unmarshal(resBytes, response)
	return response, errors.Wrap(err, "error unmarshalling Response")
}

// UnmarshalChaincodeEvents unmarshals bytes to a ChaincodeEvent
func UnmarshalChaincodeEvents(eBytes []byte) (*peer.ChaincodeEvent, error) {
	chaincodeEvent := &peer.ChaincodeEvent{}
	err := proto.Unmarshal(eBytes, chaincodeEvent)
	return chaincodeEvent, errors.Wrap(err, "error unmarshalling ChaicnodeEvent")
}

// UnmarshalProposalResponsePayload unmarshals bytes to a ProposalResponsePayload
func UnmarshalProposalResponsePayload(prpBytes []byte) (*peer.ProposalResponsePayload, error) {
	prp := &peer.ProposalResponsePayload{}
	err := proto.Unmarshal(prpBytes, prp)
	return prp, errors.Wrap(err, "error unmarshalling ProposalResponsePayload")
}

// UnmarshalProposal unmarshals bytes to a Proposal
func UnmarshalProposal(propBytes []byte) (*peer.Proposal, error) {
	prop := &peer.Proposal{}
	err := proto.Unmarshal(propBytes, prop)
	return prop, errors.Wrap(err, "error unmarshalling Proposal")
}

// UnmarshalTransaction unmarshals bytes to a Transaction
func UnmarshalTransaction(txBytes []byte) (*peer.Transaction, error) {
	tx := &peer.Transaction{}
	err := proto.Unmarshal(txBytes, tx)
	return tx, errors.Wrap(err, "error unmarshalling Transaction")
}

// UnmarshalChaincodeActionPayload unmarshals bytes to a ChaincodeActionPayload
func UnmarshalChaincodeActionPayload(capBytes []byte) (*peer.ChaincodeActionPayload, error) {

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Ensure you pass Cap.Action.ProposalResponsePayload (the action's Result field), not envelope/payload-level bytes.
2. Verify parent structures unmarshal successfully first (Envelope -> Payload -> Transaction).
3. Check non-empty, non-truncated input; log length and base64 of failing bytes.
4. Align Fabric versions between the peer that produced the transaction and the parser.
5. Fail the transaction validation cleanly with context instead of proceeding on a zero-value payload.

Example fix

// before
prp, _ := protoutil.UnmarshalProposalResponsePayload(env.Payload)
// after
act := tx.Actions[0].Payload
cha, _ := protoutil.UnmarshalChaincodeActionPayload(act)
prp, err := protoutil.UnmarshalProposalResponsePayload(cha.Action.ProposalResponsePayload)
if err != nil {
    return fmt.Errorf("bad proposal response payload: %w", err)
}

func validPRP(cha *peer.ChaincodeActionPayload) bool {
    return cha != nil && cha.Action != nil && len(cha.Action.ProposalResponsePayload) > 0
}

func isProposalResponsePayload(v any) bool {
    _, ok := v.(*peer.ProposalResponsePayload)
    return ok
}

prp, err := protoutil.UnmarshalProposalResponsePayload(cha.Action.ProposalResponsePayload)
if err != nil {
    return fmt.Errorf("invalid action payload (%d bytes): %w", len(cha.Action.ProposalResponsePayload), err)
}

When it happens

Trigger: Calling UnmarshalProposalResponsePayload on the Result field of a TransactionAction that is empty, truncated, or of another type; reached from transaction validation (validateEndorserTransaction, extractDependenciesForTx, ValidateLSCCInvocation) and endorsement processing.

Common situations: VSCC-style validation of committed transactions where action results were corrupted; parsing transactions from a different Fabric version; extracting the wrong field (action vs payload) in custom block parsers.

Understand the failure class

Background: "cannot parse invalid wire-format data", "cannot unmarshal", "failed unmarshalling": protobuf unmarshal errors explained — this error's family across 10 libraries.

Related errors

• GetProposalResponsePayload error %s
• GetChaincodeAction error %s
• error unmarshalling ProposalResponse
• error unmarshalling ChaincodeAction
• error unmarshalling Transaction

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/41fda88e3ccbb5df. Report an issue: GitHub.