Hello, everyone. Sorry to post again because my problem is not solved yet.

So at first the process of running DKE stopped because my SequenceName and the console window reads: Converting input DICOM images to NIfTI... Error using spm_dicom_convert_series_description>nii_name (line 1186)
Invalid sequence name in DICOM header! Sequence name must contain 'ep'! And later I confirmed it with Matlab and it did show that my SequenceName contains no ' ep'

Then I use following lines in Matlab to change the sequence name of my DICOM data sucessfully. 

info=dicominfo('1.3.12.2.1107.5.2.32.35420.2018010410543453162206454');
info.SequenceName = '*ep_b0';
dbstop if error

filenames = dir('*.dcm');
for i = 1: size(filenames,1)
X =dicomread(filenames(i).name);
info = dicominfo(filenames(i).name);
info.SequenceName = '*ep_b0';
% fname= ['./result/',info.MediaStorageSOPInstanceUID, '.dcm'];
fname= strcat('test',num2str(i), '.dcm');
dicomwrite(X, fname ,info)
end

So after finishing changing the SequenceName, new problems appear, and it still doesn't work. The console window reads as following:
% Fri Apr 27 01:54:55 PM
studydir = 'F:\P8';
subject_list = {''};
preprocess_options.format = 'dicom';
preprocess_options.navg = 1;
preprocess_options.extra_b0 = 0;
preprocess_options.coreg_flag = 1;
preprocess_options.series_description = {'ep2d_diff_log2_iso20_free42_B1000_p2'};
fn_img_prefix = 'rdki';
bval = [0 1000 2000];
ndir = 30;
idx_1st_img = 1;
Kmin = 0;
NKmax = 3;
Kmin_final = 0;
Kmax_final = 3;
T = 50;
find_brain_mask_flag = 1;
dki_method.no_tensor = 0;
dki_method.linear_weighting = 1;
dki_method.linear_constrained = 1;
dki_method.nonlinear = 0;
dki_method.linear_violations = 0;
dki_method.robust_option = 0;
dki_method.noise_tolerance = 0.09;
dti_method.dti_flag = 0;
dti_method.dti_only = 0;
dti_method.no_tensor = 0;
dti_method.linear_weighting = 1;
dti_method.b_value = 1e+003;
dti_method.directions{1} = [1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30];
dti_method.robust_option = 0;
dti_method.noise_tolerance = 0.09;
fn_noise = '';
fwhm_img = [3.375 3.375 3.375];
fwhm_noise = [0 0 0];
median_filter_method = 2;
map_interpolation_method.flag = 0;
map_interpolation_method.order = 1;
map_interpolation_method.resolution = 1;
fn_gradients = 'gradient_vectors_siemens30.dat';
idx_gradients{1} = [1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30];
idx_gradients{2} = [1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30];

command line: dke DKEParameters.dat
Diffusional Kurtosis Estimator (DKE) version 2.6.0, February 2015
Start date and time: April 27, 2018 13:55:07
Diffusional Kurtosis Estimator (DKE) version 2.6.0
Converting input DICOM images to NIfTI... ***************************************************
* The AcquisitionNumber counter does not appear *
* to be changing from one volume to another. *
* Another possible explanation is that the same *
* DICOM slices are used multiple times. *
* The conversion is having to guess how slices *
* should be arranged into volumes. *
* NCH_PROGLIO_001 / 9 / 1
***************************************************
complete.
Co-registering images...
Error using spm_hist2
Wrong number of dims (1).
Error in spm_coreg>optfun (line 165)
Error in spm_coreg (line 88)
Error in spm_powell (line 27)
Error in spm_coreg (line 143)
Error in dke_preprocess_dicom>coregister (line 207)
Error in dke_preprocess_dicom (line 78)
Reading input images... Error using dke_estimate (line 165)
Input NIfTI image F:\P8\intermediate_processing\combined\rdki does not exist!
Error in dke (line 182)

Does anyone know what is going on? I'm in desperate need of some suggestions!! Thank you very much.

Best regards,
Xinman