Error in gretna>PreprocessButton_Callback (line 96)
gretna_GUI_PreprocessInterface;

Error in gui_mainfcn (line 95)
feval(varargin{:});
Error in gretna (line 42)
gui_mainfcn(gui_State, varargin{:});
Error in
matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)gretna('PreprocessButton_Callback',hObject,eventdata,guidata(hObject))
Error while evaluating UIControl Callback.

 The above stuff is the Matlab error data while launching GRETNA. How should resolve this error. Please help.