I tried more than 5 times to carry out the spatial processing and i get the error below.
P,S Ive been using the same toolbox for more than a month and this just started.

Transform optode/channel positions from subject space to MNI space...
---------------------------------------------------------
Read optode, channel and (reference) positions...
Completed.

Transform subject space to MNI space using NFRI software...
Completed.
Project MNI coordinates onto the rendered brain...
Completed.
Save POS.mat...
Completed.
fNIRS measurements (NIRS.mat) are paired with channel positions (POS.mat)...
Completed.
Error using split (line 73)
Not enough input arguments.
Error in spm_fnirs_viewer_ch>spm_fnirs_viewer_ch_OpeningFcn (line 52)
colormap(split);
Error in gui_mainfcn (line 220)
feval(gui_State.gui_OpeningFcn, gui_hFigure, [], guidata(gui_hFigure), varargin{:});
Error in spm_fnirs_viewer_ch (line 26)
gui_mainfcn(gui_State, varargin{:});
Error in spm_fnirs_spatialpreproc_ui (line 121)
spm_fnirs_viewer_ch(R);
Error in spm_fnirs>push_spatial_Callback (line 63)
spm_fnirs_spatialpreproc_ui;
Error in gui_mainfcn (line 95)
feval(varargin{:});
Error in spm_fnirs (line 25)
gui_mainfcn(gui_State, varargin{:});
Error in
matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)spm_fnirs('push_spatial_Callback',hObject,eventdata,guidata(hObject))
Error while evaluating UIControl Callback.
>>