XF 1.4 Why does rebuilding user caches list more users than I have in my forum?

[jeffwidman]

On a forum with ~40K users, I click "rebuild user cache" and see "Rebuilding users (140,000)"... are these counts of the number of row updates? Or are there other user accounts I'm not finding somehow?

 

[Jake Bunce]

The cache rebuild is reporting the user_id. The maximum user_id will almost always be larger than the total number of users.