Google Colab Data Bunch 'UserWarning: Your training set is empty.'

I am having an issue creating my data bunch in Colab with my own data on Google Drive.

Specifically, I get the following error: UserWarning: Your training set is empty (see link to complete code below). I have copied the data over to my Google Drive, and I can access it in Colab…however, when I create a data bunch I get this training and validation set empty error.

Is this an incompatibility with Fastai? This code runs fine on the Kaggle Kernel. Any thoughts or advice?

(Note: Data is from Kaggle ultrasound-nerve-segmentation competition)
My code:
Code I am referencing from in Kaggle: