What causes "cannot create proposal, due to %s" in hyperledger/fabric?

Inspect the wrapped %s cause in the message — it names the exact proposal-construction failure

cannot create proposal, due to %s

Error message

cannot create proposal, due to %s

What it means

This error is returned by the `peer channel joinbysnapshot` status command when constructing the endorser proposal fails. The CLI serializes the local signer identity and calls protoutil.CreateProposalFromCIS to build a Proposal proto for the JoinBySnapshotStatus chaincode invocation; any failure there is wrapped with the underlying cause in %s.

Source

Thrown at internal/peer/channel/joinbysnapshotstatus.go:78

	return nil
}

func (cc *endorserClient) joinBySnapshotStatus() (*pb.JoinBySnapshotStatus, error) {
	var err error

	invocation := &pb.ChaincodeInvocationSpec{
		ChaincodeSpec: &pb.ChaincodeSpec{
			Type:        pb.ChaincodeSpec_Type(pb.ChaincodeSpec_Type_value["GOLANG"]),
			ChaincodeId: &pb.ChaincodeID{Name: "cscc"},
			Input:       &pb.ChaincodeInput{Args: [][]byte{[]byte(cscc.JoinBySnapshotStatus)}},
		},
	}

	var prop *pb.Proposal
	c, _ := cc.cf.Signer.Serialize()
	prop, _, err = protoutil.CreateProposalFromCIS(common2.HeaderType_ENDORSER_TRANSACTION, "", invocation, c)
	if err != nil {
		return nil, fmt.Errorf("cannot create proposal, due to %s", err)
	}

	var signedProp *pb.SignedProposal
	signedProp, err = protoutil.GetSignedProposal(prop, cc.cf.Signer)
	if err != nil {
		return nil, fmt.Errorf("cannot create signed proposal, due to %s", err)
	}

	proposalResp, err := cc.cf.EndorserClient.ProcessProposal(context.Background(), signedProp)
	if err != nil {
		return nil, fmt.Errorf("failed sending proposal, due to %s", err)
	}

	if proposalResp.Response == nil || proposalResp.Response.Status != http.StatusOK {
		return nil, fmt.Errorf("received bad response, status %d: %s", proposalResp.Response.Status, proposalResp.Response.Message)
	}

	joinbysnapshotStatus := &pb.JoinBySnapshotStatus{}

View on GitHub (pinned to 2736b63f8f)

Solutions

Inspect the wrapped %s cause in the message — it names the exact proposal-construction failure
Verify the peer CLI's MSP/identity configuration (core.yaml, --mspdir/--clientauth) so the signer serializes correctly
Re-run with the correct channel name and snapshot parameters; ensure no empty/invalid chaincode invocation arguments are passed
Regenerate the peer's local MSP certificates if the identity is expired or corrupt

Example fix

// before: signer misconfigured, error surfaces here
prop, _, err := protoutil.CreateProposalFromCIS(common2.HeaderType_ENDORSER_TRANSACTION, "", invocation, c)
if err != nil { return nil, fmt.Errorf("cannot create proposal, due to %s", err) }
// after: validate signer serialization up front
c, err := cc.cf.Signer.Serialize()
if err != nil { return nil, fmt.Errorf("signer identity not available: %w", err) }
prop, _, err = protoutil.CreateProposalFromCIS(common2.HeaderType_ENDORSER_TRANSACTION, "", invocation, c)

Defensive patterns

Strategy: validation

Validate before calling

// pre-flight: signer identity must serialize
if _, err := signer.Serialize(); err != nil {
    return fmt.Errorf("signer identity invalid, cannot build proposal: %w", err)
}

Try / catch

if err != nil {
    return nil, fmt.Errorf("cannot create proposal, due to %s", err) // log err fully for diagnosis
}

Prevention

Validate MSP directory contents before running peer channel commands
Use the same identity config that works for other peer CLI commands first
Pin CLI and peer to the same Fabric version
Check --mspdir/--clientauth flags are consistent

When it happens

Trigger: protoutil.CreateProposalFromCIS returns an error while building the ENDORSER_TRANSACTION proposal for the joinbysnapshot status query — e.g. malformed/empty channel ID or invocation input, or the signer identity cannot be constructed.

Common situations: MSP configuration is broken so the signer's serialized identity is invalid; a corrupted or partially initialized peer client config (cc.cf.Signer is nil or misconfigured); running the command before 'fetchconfig'/snapshot prerequisites are in place.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/2dd2996a3bd441f9. Report an issue: GitHub.