Invalid input parameters DisplayName

Unity Engine
,
1

Good morning, I have a “DisplayName” GameObject and has a child of “UserDisplayName” InputField. Im trying to create a new nickname for new user login. This is the error i got

Here is my code.

public InputField UserDisplayName;

public void OnUpdatePlayerName()
    {
        PlayFabClientAPI.UpdateUserTitleDisplayName(new UpdateUserTitleDisplayNameRequest
        {
            DisplayName = UserDisplayName.text
        }, result =>
        {
            DisplayNamePanel.SetActive(false);
            GameStartPanel.SetActive(true);
            Debug.Log("The player's display name is now: " + result.DisplayName);
        }, error => Debug.LogError(error.GenerateErrorReport()));
    }

4153378--366208--upload_2019-1-28_14-52-49.png

2

I alrd assign my “UserDisplayName” inputfield into the script. As you can see it in here