maximal_ball_wrapper does not work

[xiangWu-WW]

import porespy as ps
import openpnm as op
np.random.seed(10)
im = ps.generators.blobs(shape=[50,50,50])
mb = ps.networks.maximal_ball_wrapper(im,prefix='mb',path_to_exe=r'F:\PoreData\pnextract-master\pnextract-master\pnextract.exe')

ERROR:
Program: F:\PoreData\pnextract-master\pnextract-master\pnextract.exe
File: /home/aq209/tmp/pnflow/src/libvoxel/voxelImage.cpp, Line 756
Expression: readingImage

I want to extract the network generated by porespy.generators.blobs with the Maximal_ball_wrapper ,make a contrast with SNOW. But it turns out error. It maybe something wrong with Image, thus i also tried the Berea sandstone.it does not work. I not familiar with C++.