Hello -
I'm trying to add users to groups. I've created the groups via Admin > Users and Security > Groups. When I go to the 'Staff' Group, I cannot drop in the CSV file (that gets downloaded again to my desktop), nor can I add individual users (the screen shows 'no users found'):

What can be preventing it? I've got Jira and RefinedWiki plugins, but those shouldn't be interfering with the permissions, right?
Thanks,
Susan