PostTransaction function returns Request Unsuccessful 426

[muhammadramis]

I am using golang, and upon posting a transaction the server is returning a 426.
this is the code i am using as an example.

cfg := cl.ClientConfig{
		Url: "http://192.168.100.10/api/v1/",
	}
	client, _ := cl.New(cfg)
	var data transaction.Asset
	data.Data = make(map[string]interface{})
	data.Data["test"] = "hello world"
	metadata := make(map[string]interface{})
	metadata["test"] = "hello world"
	var outputs []transaction.Output
	var issuers []ed25519.PublicKey
	var keyPairs []*transaction.KeyPair
	keyPair, err := transaction.NewKeyPair()
	fmt.Println(err)
	keyPairs = append(keyPairs, keyPair)
	for _, keyPair := range keyPairs {
		condition := transaction.NewEd25519Condition(keyPair.PublicKey)
		output, err := transaction.NewOutput(*condition, "1")
		if err != nil {
			fmt.Println("Cannot Create outputput!")
		}
		outputs = append(outputs, output)

		//Create Issuers

		issuers = append(issuers, keyPair.PublicKey)
	}
	txn, err := transaction.NewCreateTransaction(data, metadata, outputs, issuers)
	if err != nil {
		fmt.Println(err)
	} else {
		err = txn.Sign(keyPairs)
		if err != nil {
			fmt.Printf("Not Signed ! %s\n", err.Error())
		} else {
			fmt.Println("*** SIGNED TXN:")
			fmt.Println(txn.String())
		}
	}
	block1, err := client.GetBlock("0")
	if err != nil {
		fmt.Println("get block failed")
		fmt.Println(err)
	} else {
		fmt.Println(block1.Height)
	}
	err = client.PostTransaction(txn)
	if err != nil {
		fmt.Printf("Failed : %s\n", err.Error())
	} else {

	}