Reference to non-existent field 'output' Error

Hello,

I'm afraid I can't find my mistake. The program is without problems so far and now I get the following error when starting the program:

Reference to non-existent field 'output'.

Error in Spiel>Spiel_OutputFcn (line 46)

varargout{1} = handles.output;

Error in gui_mainfcn (line 264)

feval(gui_State.gui_OutputFcn, gui_hFigure, [], gui_Handles);

Error in Spiel (line 16)

gui_mainfcn(gui_State, varargin{:});

My programming skills are not good, but it should be understandable ;)

function varargout = Spiel(varargin)
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @Spiel_OpeningFcn, ...
                   'gui_OutputFcn',  @Spiel_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT



function Spiel_OpeningFcn(hObject, ~, handles)
    handles.Flag = 0;
    handles.Flag2 = 0;
    handles.Plotsize=0.0015;
    handles.Database = load('Database.mat');
    handles.Logo = imread('Logo.png');
    handles.Logo_small = imread('Logo_small.png');
    handles.Correct.Right = 0;
    handles.Correct.Count = 0;
    handles.Correct.Percent = 0;
     
    axes(handles.Plot_small)
    imshow(handles.Logo_small)
    
    axes(handles.Plot)
    set(handles.Plot,'visible','off');
    imshow(handles.Logo)
    
    % Update handles structure
    guidata(hObject, handles);


function varargout = Spiel_OutputFcn(~,~, handles) 

varargout{1} = handles.output;


function B_New_Callback(hObject, ~, handles)
    Stadtteil = 0;
    handles.Flag = 1;
    handles.Flag2 = 0;
    set(handles.B_Solution,'BackgroundColor',[0.94 0.94 0.94]);
    set(handles.B_Solution, 'string', 'Lösung anzeigen');
    % reset plot window
    axes(handles.Plot)
    cla('reset')
    imshow(handles.Logo)
    
    while Stadtteil == 0
        StadtteilR = randi(5);
        
        if get(eval(['handles.C_' num2str(StadtteilR)]), 'Value') == 1
            Stadtteil = StadtteilR;
        end
        
    end

    switch Stadtteil
        case 1
            handles.Stadtteilname = 'Kernstadt';
        case 2
            handles.Stadtteilname = 'Heilsberg';
        case 3
            handles.Stadtteilname = 'Massenheim';
        case 4
            handles.Stadtteilname = 'Dortelweil';
        case 5
            handles.Stadtteilname = 'Gronau';
    end  
    
    handles.Strasse = randi(length(eval(['handles.Database.' handles.Stadtteilname '.Street'])));
    
    set(handles.T_Street, 'String', eval(['handles.Database.' handles.Stadtteilname '.Street(' num2str(handles.Strasse) ')']))
    guidata(hObject, handles);

    
function B_Solution_Callback(hObject, ~ , handles)
set(hObject, 'UserData', true);
    if handles.Flag == 0
        return
    end
    
    handles.Flag2 = 1;
    handles.Correct.Count = handles.Correct.Count + 1;

    if strcmp(handles.Stadtteilname, handles.SelectStadtteil) == 1
        set(handles.B_Solution,'BackgroundColor','green');
        set(handles.B_Solution, 'string', 'Richtig!');
        handles.Correct.Right = handles.Correct.Right + 1;
    else
        set(handles.B_Solution,'BackgroundColor','red');
        set(handles.B_Solution, 'string', ['Falsch, richtig ist ' handles.Stadtteilname]);
    end
    
    handles.lon = eval(['handles.Database.' handles.Stadtteilname '.lon(' num2str(handles.Strasse) ')']);
    handles.lat = eval(['handles.Database.' handles.Stadtteilname '.lat(' num2str(handles.Strasse) ')']);
    
    guidata(hObject, handles);
    Plotting(handles)
    Lights(hObject,handles)
    

function Lights(hObject,handles)
    handles.Correct.Percent = handles.Correct.Right / handles.Correct.Count;
    
    if handles.Correct.Percent > 0.8
        set(handles.T_Lights, 'BackgroundColor',[0 1 0])
    elseif handles.Correct.Percent > 0.4
        set(handles.T_Lights, 'BackgroundColor',[1 1 0])
    else
        set(handles.T_Lights, 'BackgroundColor',[1 0 0])
    end
        
    set(handles.T_Lights, 'string', sprintf('%d %% ', round(handles.Correct.Percent*100,0)));
    
    guidata(hObject,handles);
    
function Plotting(handles)
    plot(handles.lon, handles.lat, '.r', 'MarkerSize', 20)
    set(handles.Plot,'visible','off');
    handles.Plot = Map([handles.lon-(handles.Plotsize*1.57) handles.lon+(handles.Plotsize*1.57) handles.lat-handles.Plotsize handles.lat+handles.Plotsize]);
	
    handles.Flag2 = 1;
    

function R_1_Callback(hObject, ~, handles)
    handles.SelectStadtteil = 'Kernstadt';
    guidata(hObject, handles);
function R_2_Callback(hObject, ~, handles)
    handles.SelectStadtteil = 'Heilsberg';
    guidata(hObject, handles);

function R_3_Callback(hObject, ~, handles)
    handles.SelectStadtteil = 'Massenheim';
    guidata(hObject, handles);

function R_4_Callback(hObject, ~, handles)
    handles.SelectStadtteil = 'Dortelweil';
    guidata(hObject, handles);

function R_5_Callback(hObject, ~, handles)
    handles.SelectStadtteil = 'Gronau';
    guidata(hObject, handles);


function C_1_Callback(~, ~, ~)
function C_2_Callback(~, ~, ~)
function C_3_Callback(~, ~, ~)
function C_5_Callback(~, ~, ~)
function C_4_Callback(~, ~, ~)

Answer 1

[Matt J]

I don't see where you've created handles.output. So, no wonder Matlab complains that it can't find it.

[Cross]

I didn't write this function, it was created automatically. Where do I have to insert which code?

I am still a newbie

[Matt J]

If you don't care what output the GUI returns, you can just change the OutputFcn to return something arbitrary,

function varargout = Spiel_OutputFcn(~,~, handles) 
  varargout{1} = [];
end