IndexError: list index out of range

[nmweizi]

img = Image.open('3LLW.png')
img1 = pycapt.two_value(img,Threshold=100)
img1.show()
img_list = pycapt.cut_img_to_img_list(img1,max_width=60,background=255)

Traceback (most recent call last):
File "extract_single_letters_from_captchas.py", line 29, in
img_list = pycapt.cut_img_to_img_list(img1, max_width=30, background=255)
File "d:\python36\lib\site-packages\pycapt_init_.py", line 74, in cut_img_to_img_list
return pycapt.solve_it.cut_img_to_img_list(image,max_width,background=255)
File "d:\python36\lib\site-packages\pycapt\solve_it_init_.py", line 55, in cut_img_to_img_list
mode_list = pycapt.solve_it.cut_img.cut_img(image,max_width)
File "d:\python36\lib\site-packages\pycapt\solve_it\cut_img.py", line 139, in cut_img
li = cut_mode(my_mode,max_width=30)
File "d:\python36\lib\site-packages\pycapt\solve_it\cut_img.py", line 66, in cut_mode
alpha_list = list(range(i,bian_yuan[(k+1)*2-1]+1))
IndexError: list index out of range

[aboutmydreams]

max_width is too big ?

[nmweizi]

max_width=20，It's still the same