Unable to Append ERP datasets

[gopioptom]

Here is the error from matlab

Error using textscan
Invalid file identifier. Use fopen to generate a valid file identifier.

Error in appenderpGUI>setbuttonsgui (line 954)
formcell = textscan(fid_list, '%[^\n]','CommentStyle','#', 'whitespace', '');

Error in appenderpGUI>appenderpGUI_OpeningFcn (line 80)
handles = setbuttonsgui(hObject, eventdata, handles);

Error in gui_mainfcn (line 220)
feval(gui_State.gui_OpeningFcn, gui_hFigure, [], guidata(gui_hFigure), varargin{:});

Error in appenderpGUI (line 42)
[varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});

Error in pop_appenderp (line 104)
answer = appenderpGUI(nloadedset, def);

Error while evaluating Menu Callback.