I get error when I closed the window before selected the stop button for live video

I have the following code for live video:

 function track_OpeningFcn(hObject, eventdata, handles, varargin)
  movegui(hObject,'center')
  imaqreset
  vid = videoinput('winvideo',1);
  handles.video = vid;
  set(handles.video,'TimerPeriod', 0.05, ...
  'TimerFcn',['if(~isempty(gco)),'...
  'handles=guidata(gcf);'... 
  'image(getsnapshot(handles.video));'... 
  'set(handles.axes2,''ytick'',[],''xtick'',[]),'...
  'else '...
  'delete(imaqfind);'... % Clean up - delete any image acquisition objects
  'end']);
  triggerconfig(handles.video,'manual');
  handles.video.FramesPerTrigger = Inf; 
  handles.output = hObject;
  % Update handles structure
  guidata(hObject, handles);
  uiwait

 function StartVideo_Callback(hObject, eventdata, handles)
 vid = handles.video;
 start (vid);
guidata(hObject, handles)

function StopVideo_Callback(hObject, eventdata, handles)
vid = handles.video;
stop (vid);
guidata(hObject, handles)

function track_CloseRequestFcn(hObject, eventdata, handles)
uiresume
delete(hObject)
delete (handles.video)
imaqreset

I get this error when I closed the window before selected the stop button:

Error using imaqdevice/getsnapshot (line 65)
Image acquisition object OBJ has been deleted. OBJ is now an invalid object.