TypeError: Cannot read property '_uploadFiles' of undefined in google colaboratory

Well, if running on Brave Browser, i can confirm that turning down the shields will do the job.

Navigate to chrome://settings/content/cookies and turn off "block third-party cookies". It works for me!

In order to upload the file "YOURFILE.csv" in your directory 'YOURDIRECTORY', You can upload the directory into google drive, and do the following.

from google.colab import drive
drive.mount('/content')

Then if you see the content of your current directory, you see the "My Drive" which is your google drive and now you can have access to the files saved in your google drive. !ls command shows you the current directory content.

Now you can import your file into the current colab:

your_data = pd.read_csv("./My Drive/YOURDIRECTORY/YOURFILE.csv")