Sign in link broken

I was having the same problem, but just figured it out and got UnityHub to login in after 2-3 days of trying. There were two problems I had to overcome.

First, Unity’s authentication method is sending a URL back to the browser that is supposed to communicate with the UnityHub app on your computer. However, it has the unityhub protocol and by default your operating system (Linux in my case) and your browser (Firefox) don’t know how to deal with that protocol (as opposed to http for example). I discovered this by looking at the Firefox inspection console, which gave an error similar to:

So the first thing to do is to associate the protocol with the Unity Hub app. The info from this link got me most of the way there.

But you also need to make sure to reload the file in the OS before it becomes active:

I use KDE/Plasma, so nothing here is really Gnome specific. I don’t know how this stuff works on Windows, but hopefully knowing what the problem is will help.

The second issue was that Firefox was preventing the authorization script from executing (until I authorized it). To fix this issue you have to open up the Web Developer Tools and open the console. You should see a warning line similar to this:

The text **authorize** should be a clickable link. Clicking on it will authorize the request and send the data back to the UnityHub app and successfully log you in.

Hope this helps