dont know what the problem

hi
I wrote this code:

public class MenuManager : MonoBehaviour 
{
	public string CurrentMenu;
	public string matchName = "";
	public string matchPassword = "";
	public int matchMaxplayers = 32;
	public HostData match;
	
	private Vector2 ScrollLobby = Vector2.zero;
	
	void Start()
	{
		CurrentMenu = "Main";
		matchName = "PixelWarz" + Random.Range(0,5000);
	}
	
	void OnGUI()
	{
		if (CurrentMenu == "Main")
			Main_Menu();
		if (CurrentMenu == "Lobby")
			Main_Lobby();
		if (CurrentMenu == "Host")
			Menu_Gamehost();
	}
	
	public void NavigateTo(string nextMenu)
	{
		CurrentMenu = nextMenu;
	}
	private void Main_Menu()
	{
		if(GUI.Button(new Rect(10,10,200,50),"Host Game"))
		{
			NavigateTo("Host");
		}
		
		if(GUI.Button(new Rect(10,70,200,50),"Refresh"))
		{
			MasterServer.RequestHostList("DeathMatch");
		}
		
		GUI.Label(new Rect(220,10,130,30),"Player Name:");
		MultiplayerManager.instance.playerName = GUI.TextField(new Rect(350,10,150,30),MultiplayerManager.instance.playerName);
		if(GUI.Button(new Rect(510,10,100,30),"Save Name"))
		{
			PlayerPrefs.SetString("Player Name",MultiplayerManager.instance.playerName);
		}
		
		GUILayout.BeginArea(new Rect(Screen.width - 400,0,400,Screen.height),"Server List","Box");
		
		foreach(HostData match in MasterServer.PollHostList);   
		{
		  GUILayout.BeginHorizontal("Box");
		
			GUILayout.Label(match.gameName);
			if(GUILayout.Button("Connect"))
			Network.Connect(match);
			
			GUILayout.EndHorizontal();
		}
		
		GUILayout.EndArea();
	}
	
	private void Menu_Gamehost()
	{
		if(GUI.Button(new Rect(10,10,200,50),"Back"))
		{
			NavigateTo("Main");
		}
		if(GUI.Button(new Rect(10,60,200,50),"Start Server"))
		{
			MultiplayerManager.instance.startServer(matchName,matchPassword,matchMaxplayers);
		}
		GUI.Label(new Rect(220,10,130,30),"Match Name:");
		matchName = GUI.TextField(new Rect(400,10,200,30),matchName);
		
		GUI.Label(new Rect(220,50,130,30),"Match Password:");
		matchPassword = GUI.PasswordField(new Rect(400,50,200,30),matchPassword,'*');
		
		GUI.Label(new Rect(220,90,130,30),"Match Max Players");
		GUI.Label(new Rect(400,90,200,30),matchMaxplayers.ToString());
		matchMaxplayers = Mathf.Clamp(matchMaxplayers,8,32);
		
		if(GUI.Button(new Rect(425,90,25,30),"+"))
			matchMaxplayers += 2;
		if(GUI.Button(new Rect(450,90,25,30),"-"))
			matchMaxplayers -= 2;
	}
	
	private void Main_Lobby()
	{
		ScrollLobby = GUILayout.BeginScrollView(ScrollLobby,GUILayout.MaxWidth(200));
		
		foreach(mpPlayer pl in MultiplayerManager.instance.playerList)
		{
			GUILayout.Box(pl.playerName);
		}	
			
		GUILayout.EndScrollView();
	}
	
	void OnServerInitialized()
	{
		NavigateTo("Lobby");
	}
	
	void OnConnectedToServer()
	{
		NavigateTo("Lobby");
	}
}

and the unity say:Assets/Scripts/MenuManager.cs(57,56): error CS0446: Foreach statement cannot operate on a `method group’
and i dont know what the problem
someone can tell me what the problem is?
thx for all the helpers

Try with

foreach(HostData match in MasterServer.PollHostList());

instead of

foreach(HostData match in MasterServer.PollHostList);

it fix the problem less or more
i can play the game but it says now:NullReferenceException: Object reference not set to an instance of an object
MenuManager.Main_Menu () (at Assets/Scripts/MenuManager.cs:61)
MenuManager.OnGUI () (at Assets/Scripts/MenuManager.cs:25)
what is that mean?

61 and 25 are line numbers. Look at those lines and see if you can figure out what’s wrong.