hyperledger/fabric · error

error unmarshalling Response

Error message

error unmarshalling Response

What it means

Returned by protoutil.UnmarshalResponse when proto.Unmarshal cannot decode bytes into a peer.Response message. The wrapper names the failing message type in the error. It indicates the bytes are not a valid Response (the chaincode invocation's status/message/payload structure).

Source

Thrown at protoutil/unmarshalers.go:130

// UnmarshalProposalResponse unmarshals bytes to a ProposalResponse
func UnmarshalProposalResponse(prBytes []byte) (*peer.ProposalResponse, error) {
	proposalResponse := &peer.ProposalResponse{}
	err := proto.Unmarshal(prBytes, proposalResponse)
	return proposalResponse, errors.Wrap(err, "error unmarshalling ProposalResponse")
}

// UnmarshalChaincodeAction unmarshals bytes to a ChaincodeAction
func UnmarshalChaincodeAction(caBytes []byte) (*peer.ChaincodeAction, error) {
	chaincodeAction := &peer.ChaincodeAction{}
	err := proto.Unmarshal(caBytes, chaincodeAction)
	return chaincodeAction, errors.Wrap(err, "error unmarshalling ChaincodeAction")
}

// 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) {

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Ensure the bytes are the Response field of ProposalResponsePayload (prp.Response), not the whole payload or extension.
2. Check len(resBytes) > 0 before unmarshaling; return a clear error for absent responses.
3. Align protobuf/Fabric versions between producer and consumer of the response.
4. Avoid re-encoding responses through text formats (JSON/base64 round trips) that can corrupt them.
5. Handle the error by returning the failure to the caller instead of using a zero-value Response.

Example fix

// before
res, _ := protoutil.UnmarshalResponse(prp.Extension)
// after
res, err := protoutil.UnmarshalResponse(prp.Response)
if err != nil {
    return fmt.Errorf("bad chaincode response: %w", err)
}

func validResponse(prp *peer.ProposalResponsePayload) bool {
    return prp != nil && len(prp.Response) > 0
}

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

res, err := protoutil.UnmarshalResponse(prp.Response)
if err != nil {
    return fmt.Errorf("invalid chaincode response: %w", err)
}

When it happens

Trigger: Calling UnmarshalResponse on response bytes that are empty, truncated, or actually another message type (e.g. ChaincodeAction bytes); reached from TestProposalResponse and endorsement result processing.

Common situations: Extracting the response from the wrong field of a ProposalResponsePayload; processing responses written/read with mismatched protobuf schemas; corrupted stored endorsements.

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

• error unmarshalling ChaincodeHeaderExtension
• error unmarshalling ChaincodeAction
• error unmarshalling ChaicnodeEvent
• error unmarshalling
• error unmarshalling original config

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/1f66b37e4e09a0fc. Report an issue: GitHub.