When I get emails for these types of notifications: "New Thread to Watched Forum", there is a broken link in the email. In the email message it displays the title of the thread and a text URL which both point to the same link and a "View this Thread' button which points to a different URL.
The text link gives an error, the button link works correctly.
This is the text link
This is the button link:
The text link gives an error, the button link works correctly.
This is the text link
This is the button link: