You are not authorised to view this resource.
You need to login.
But, there was no login prompt. I browsed around the website and the only place I found a login prompt (I did not do an exhaustive search) was on the main forum screen. I have browsed the forum pages before and been given a login prompt when I attempted to reply to a post.
It would be nice to have a login prompt when this error message is displayed. After logging in and then clicking the link from the e-mail, a new window opened in my browser and I was still shown the error message. I suppose the forum connection is specific to the browser window that I have opened.
Oh, the word "authorised" is a British spelling. The American spelling is "authorized."