I have the same problem. I have tried all the volume templates that come with BrainNet Viewer but when I load my .hdr file it 'freezes'. Matlab says 'busy' for hours. When I Ctr+C out of it, I get different things every time, like the following:

Operation terminated by user during num2str>convertUsingRecycledSprintf (line 200)In num2str>handleNumericPrecision (line 181)        s = convertUsingRecycledSprintf(x, precision);In num2str (line 84)            [s, forceWidth, f] = handleNumericPrecision(x, d);In BrainNet_Option>Initialization (line 787)            textcell{i} = ['ROI ',num2str(EC.vol.roi.drawt(i))];In BrainNet_Option>BrainNet_Option_OpeningFcn (line 79)Initialization(handles);In gui_mainfcn (line 221)    feval(gui_State.gui_OpeningFcn, gui_hFigure, [], guidata(gui_hFigure), varargin{:});In BrainNet_Option (line 52)    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});In BrainNet>LoadFile_ClickedCallback (line 3223)    H=BrainNet_Option;In gui_mainfcn (line 96)        feval(varargin{:});In BrainNet (line 53)    gui_mainfcn(gui_State, varargin{:});In @(hObject,eventdata)BrainNet('LoadFile_ClickedCallback',hObject,eventdata,guidata(hObject)) Interrupt while evaluating uipushtool ClickedCallback.


Or:





Operation terminated by user during int2str (after line 32)In num2str (line 68)                s = int2str(x); % Enhance the performanceIn BrainNet_Option>Initialization (line 787)            textcell{i} = ['ROI ',num2str(EC.vol.roi.drawt(i))];In BrainNet_Option>BrainNet_Option_OpeningFcn (line 79)Initialization(handles);In gui_mainfcn (line 221)    feval(gui_State.gui_OpeningFcn, gui_hFigure, [], guidata(gui_hFigure), varargin{:});In BrainNet_Option (line 52)    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});In BrainNet>LoadFile_ClickedCallback (line 3223)    H=BrainNet_Option;In gui_mainfcn (line 96)        feval(varargin{:});In BrainNet (line 53)    gui_mainfcn(gui_State, varargin{:});In @(hObject,eventdata)BrainNet('LoadFile_ClickedCallback',hObject,eventdata,guidata(hObject)) Interrupt while evaluating uipushtool ClickedCallback.