我想在fabric chaincode中使用gRPC来实现跨链通信，而不是使用fabric SDK。但是当我在fabric-sample/test-network上调用chaincode函数时，总是出现错误。

Error: endorsement failure during invoke. response: status:500 message:"error in simulation: failed to execute transaction eb5e480bd4075a767f56ae263741ca0f5f19620ef88952e26b7f1952bdbe83cd: could not launch chaincode chaincode_1.2:d3f97f15a635e73d3de230c8e5899e5fb95a68cf897c03e19f9e4eeca7ca3fd5: chaincode registration failed: container exited with 2"

谁能告诉我是什么原因导致这个错误？我的chaincode有bug或者gRPC不能在chaincode函数中使用？
关于gRPC的chaincode：

func (s *SmartContract) begin(ctx contractapi.TransactionContextInterface) error {
    server.Main()
    return nil
}

func (s *SmartContract) client(ctx contractapi.TransactionContextInterface) error {
    // client.Clientfunc is the client main function
    client.Clientfunc(Xt, R, sign, m)
}

server.go

func Main() {
    listen, err := net.Listen("tcp", ":9090")
    if err != nil {
        fmt.Printf("failed to listen: %v", err)
        return
    }
    grpcServer := grpc.NewServer()
    pb.RegisterSendServiceServer(grpcServer, &server{})
    err2 := grpcServer.Serve(listen)
    if err2 != nil {
        fmt.Printf("failed to serve: %v", err2)
        return
    }
}

client.go

func Clientfunc(Xt *btcec.PublicKey, R *btcec.PublicKey, s *big.Int, m []byte) []byte {
    conn, err := grpc.Dial("127.0.0.1:9090", grpc.WithTransportCredentials(insecure.NewCredentials()))
    if err != nil {
        log.Fatalf("did not connect: %v", err)
    }
    defer conn.Close()
    client := pb.NewSendServiceClient(conn)
    output := &pb.SignInput{
        XtX: Xt.X().Int64(),
        XtY: Xt.Y().Int64(),
        M:   m,
        RX:  R.X().Int64(),
        RY:  R.Y().Int64(),
        S:   s.Int64(),
    }
    resp, _ := client.Send(context.Background(), output)
    return resp.GetM()
}