Unity HostData array issues - unity3d

Question

So my problem is that whenever i try and call the hostData array with a button it returns null, but I know its not null. I even put a debug.log calling the the first member of the HostData array in update() and get when hostData != null it returns every frame but whenever i call it from the button it says its null, i even used if(hostData == null) to verify it. What could possibly cause this?
private HostData[] hostData;
private bool refreshing = false;
private Text joinServerText;
private GameObject joinServerButton;
private GameObject startServerButton;
private GameObject refreshServerButton;
void Awake()
{
joinServerButton = GameObject.Find ("JoinServerButton");
joinServerText = GameObject.Find("JoinServerText").GetComponent<Text>();
startServerButton = GameObject.Find ("StartServerButton");
refreshServerButton = GameObject.Find ("RefreshServerButton");
}
void Start()
{
joinServerButton.SetActive (false);
}
void StartServer()
{
bool useNat = !Network.HavePublicAddress();
Network.InitializeServer(2,25000, !useNat);
MasterServer.RegisterHost(gameName,"Tutorial Game Name","This is a tutorial game");
}
void refreshHostList()
{
MasterServer.RequestHostList(gameName);
refreshing = true;
}
void Update()
{
if (refreshing)
{
if(MasterServer.PollHostList().Length > 0)
{
refreshing = false;
Debug.Log (MasterServer.PollHostList().Length);
hostData = MasterServer.PollHostList();
}
}
if(hostData != null)
{
joinServerButton.SetActive (true);
joinServerText.text = hostData[0].gameName;
Debug.Log ("hostData[0].gameName");
}
}
//Messages
void OnServerInitialized()
{
Debug.Log ("Server Initialized!");
}
void OnMasterServerEvent(MasterServerEvent mse)
{
if(mse == MasterServerEvent.RegistrationSucceeded)
{
Debug.Log ("Registered Server");
}
}
//UI
public void StartSeverButton()
{
Debug.Log ("Starting Server...");
StartServer();
}
public void RefreshHostsButton()
{
Debug.Log ("Refreshing Hosts...");
refreshHostList();
}
public void JoinServerButton()
{
//for(int i=0; i<hostData.Length; i++)
//{
if (hostData == null) <--------- My problem
{
Debug.Log("hostData is null");
//Debug.Log (hostData[0].gameName);
//Network.Connect (hostData[0]);
}
}
}

Answer 1

I usually solve problems of mysterious bad value assignment by replacing this:
private HostData[] hostData;
With this:
private HostData[] _hostData;
private HostData[] hostData { get { return _hostData; } set { _hostData=value; Debug.Log("Host data set. Is null?: "+(_hostData == null), this); } }
Run it, and you'll immediately see when the variable is being set to null. And maybe you'll discover that the problem isn't what you thought--for example, maybe it's never set, and there are actually multiple instances of that class, and the one that prints the host count isn't the same instance that has the null variable.