Whenever I run the BrainNet Viewer GUI and try to load in a map file, it gives me these errors:

Error using BrainNet_spm_slice_vol
BrainNet_spm_slice_vol.c not compiled - see Makefile

Error in BrainNet_spm_read_vols (line 34)
        Y(:,:,p,i) = BrainNet_spm_slice_vol(V(i),BrainNet_spm_matrix([0 0 p]),V(i).dim(1:2),0);

Error in BrainNet_LoadFiles>VF_load (line 473)
vol=BrainNet_spm_read_vols(hdr);

Error in BrainNet_LoadFiles>OK_button_Callback (line 199)
                        [surf.hdr,surf.vol]=VF_load(filename);

Error in gui_mainfcn (line 95)
        feval(varargin{:});

Error in BrainNet_LoadFiles (line 56)
    gui_mainfcn(gui_State, varargin{:});

Error in matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)BrainNet_LoadFiles('OK_button_Callback',hObject,eventdata,guidata(hObject))
 
Error while evaluating UIControl Callback.