Problem: Expanding "Your Notifications" link from any page and clicking on any of the "New" links (New Likes Received, New Mentions, New Thread Tags, New Post Quotes, New Hash Tags) all go to a page that says only "Error: Undefined constant "buddylist" in ..../includes/class_userprofile.php on line 797"

Desktop or mobile? Desktop (never tried in Mobile)
Reproduced in multiple browsers? Which do/don’t work (we at least need to know the initial browser)? Tried Chrome, Firefox, Opera, and Safari, none work (really don't think it's a browser specific issue)
Steps to reproduce the issue: 1. Log in as hailstorm. 2. Expand the Your Notifications section on any page. 3. Select any of the "New" links (New Likes Received, New Mentions, New Thread Tags, New Post Quotes, New Hash Tags) Example: https://www.flyertalk.com/forum/memb...likes_received
Reproduced on incognito mode/private window? No. Issue only occurs when logged in (e.g. I can see the above link when not logged in)
When did this problem start? Several months ago.