What's the Solved part of my profile?

I was looking at my profile for an old post, when I spotted the Solved portion of my activity and was wondering about it as it seems to be empty for me, and all the people I've checked don't have anything either. Also, when I thought to look at users sorted by Solved, there wasn't even an option
Here's what I'm talking about:

@staff You have the Solved plugin enabled on this forum, but you don't have it enabled on any categories. That doesn't make any sense.

I'd probably just turn the plugin completely off if I were you.


Ping @steveklabnik (who I assume might have the permissions to modify this stuff).

Me, or @notriddle
Don't worry I'll do it.