Error converting Nii to Nifti pairs

Hello,

I am new to REST and I've trying to convert nifti 4d to nifti pairs. I have SPM12, Matlab R12b and REST v1.7 but the following error appears on Matlab. I have double-checked my addpaths to SPM, restarted Matlab and ran 'rest_Fix_Read_Write_Error' and nothing seems to work.

Error using rest_Fix_Read_Write_Error (line 64)
Meet error while fixing read write error. Please restart MATLAB, and run
"rest_Fix_Read_Write_Error" before starting anything.

Error in rest_ReadNiftiImage (line 100)
    rest_Fix_Read_Write_Error; %YAN Chao-Gan, 100426.

Error in rest_Nii2NiftiPairs (line 23)
    [Data, Head] = rest_ReadNiftiImage(PI,'all');

Error in rest_Nii2NiftiPairs_gui>btnRun_Callback (line 199)
    rest_Nii2NiftiPairs(ImgFileList{i},PO);

Error in gui_mainfcn (line 96)
        feval(varargin{:});

Error in rest_Nii2NiftiPairs_gui (line 26)
    gui_mainfcn(gui_State, varargin{:});
 
Error while evaluating uicontrol Callback

Any idea of what is happening? 
Thanks a loT!