[jonathansampson]

The user attempted to install an extension; this results in a request to Google's Servers (which Brave proxies to prevent users from making unintended contact with Google). If Brave's proxy happened to return a 401 response (requesting authentication), then the user would see the "Access Denied" message shown in their screenshot. It's also possible that this message could have come from Google's own server (via the Brave proxy). It's not possible to tell from the data available.

We're looking into this from our end, to see if there were any recent proxy-interruptions which might explain the user's experience.

Sampson (Brave Team)

[jonathansampson]

Resolved: User had a very out-of-date build of Brave. See https://news.ycombinator.com/item?id=29471236 for more details.