Question Deleting moderator when username is already deleted

Ok, I don't have a diploma in computer sciences and I'm not the owner of the forum, but I do have full access to the backpanel and I'm usually quite capable of finding everything I need on my own . But here's the problem. A while ago, the useraccount of a person whom was moderator of virtually all forums, was deleted (due to personal issues). The consequence is that now, in the list of moderators beneath the description of each forum, there is a blank space, i.e. like this:
"Mod1, Mod2, , Mod3"
When I go to each forum's administration, and scroll down to the list of moderators, there is (obviously) a 'blank' moderator. I noticed there's a checkbox on the left next to each moderator's name, but I wonder what it's for as I don't see any buttons which allow me to do anything with the selected moderators (i.e. delete/unpublish/...)?
Quite obviously, I can't go to the userslist and demote the user either as they're not there anymore.
So, is there any way I can solve this issue?
I know it's not really a big issue, but the blank spaces bug me .

P.S. Not sure whether I posted this in the right forum or not. Feel free to move it to the best appropriate forum.

Hello,

I you know the userid of this deleted user, you can check in table jos_fb_moderation if is still exist. If is still exist, so delete the item.

Thanks. I had such problem. But now it is solved.