I just purchased and installed the User Mentioning Addon.
When typing the @ symbol while typing a post, no names show up to choose from.
Also, if I click the @ symbol on the toolbar, again no names show up to choose from.
Our Members are not listed publically in the Members list - we need to keep our Members private. Therefore, I have turned OFF the "Display On Members List" in the Usergroup Settings for "Registered" users. I am GUESSING this is the reason none of our Members are showing up in the User Mentioning Addon, because when I turn this option back ON, some of the members show up with the User Mentioning Addon (but only members who have already contributed to that topic thread). If this "Display On Members List" is the cause of the User Mentioning Addon to not work, then the addon is useless for anyone wishing to keep their Member list not visible to the public.
Is there some other issue that would be causing the User Mentioning Addon to NOT display any registered users?