Error in running iris_extraction_3.py

[GothamPhantom]

I've done as per instruction which is to change the directory name for the dataset and limit it to 42 dataset classes. I tried running iris_extraction_3.py on Windows cmd and it was running smoothly in the beginning but then got this error at the end:

total_iris_found = 404
total images number 404
the image threshold = 20
the image name 0

Traceback (most recent call last):
File "D:\gpt4all\gpt4all-j-v1.3-groovy\notes and sample\Iris Recognition\iris-Recognition-Casia-Interval-v4-master\iris_extraction_3.py", line 248, in
, contours, = cv2.findContours(working_img, cv2.RETR_TREE, cv2.CHAIN_APPROX_NONE)
^^^^^^^^^^^^^
ValueError: not enough values to unpack (expected 3, got 2)