Object Detection Error w/ 6 lines of code, pls help!

Mr. Olefenwa,
I have followed the steps listed in your article “Object Detection with 6 lines of Code” and continue to get the following error: TypeError: object of type ‘NoneType’ has no len()
I am using custom objects (250 pictures in total) and am running the code through MacOsx terminal
When trying to run the code through google collab as you suggested the code did not compile at the last step so that is why I am using terminal, also successfully ran “Object Detection with 10 lines of code” through this platform.
Thank you so much,
Meel

Training on: None
Training with Batch Size: 4
Number of Experiments: 100
Traceback (most recent call last):
File “molestest.py”, line 7, in
trainer.trainModel()
File “/usr/local/lib/python3.7/site-packages/imageai/Detection/Custom/init.py”, line 233, in trainModel
norm=normalize
File “/usr/local/lib/python3.7/site-packages/imageai/Detection/Custom/generator.py”, line 36, in init
if shuffle: np.random.shuffle(self.instances)
File “mtrand.pyx”, line 4068, in numpy.random.mtrand.RandomState.shuffle
TypeError: object of type ‘NoneType’ has no len()

I am facing the same problem.