I've had 2 notifications now for several weeks, they're "likes" , when I click on that topic to delete the notifications I get "page not available"..... Just FYI EDIT: Apparently that only happens from the front page, when I clicked on it just now from this page it opened the "likes" page just fine.
I've seen that and have an open support ticket with vBSEO, the company that created that add on to their product. Drives me bonkers too...
The fix went in this morning. I did some testing and it worked. Please let me know if you find any issues with the updated code.