I have a tfevent file already present on my Drive and I have successfully connected it to Google Colab. After searching within the issues of Tensorboard Github, I found that I had to set dom.serviceWorkers.enabled to True which I have done. But on Google Colab after performing the two steps:

1. %load_ext tensorboard
2. %tensorboard --logdir path/to/logs

I am getting a Error 403 on the second step cell:

I am using Firefox version 81.0.1 (64-bit) and my default mode is Private Window, so history and cache are cleared after I close all browser window.

Can someone help me with this?

It seems that Tensorboard needs you to enable third party cookies to run without returning a HTTP 403 (Forbidden) error.

I had the same issue using Chrome and fixed it by just allowing everything:

You can do the same on Firefox like so:

You could also find out which exact cookie is needed and then just allow that one.