This question is in reference to Atlassian Documentation: Manage users and groups
I am a site-admin but unable to add another user to site-admins group. I click "Add" button, type in the user (or select from suggestion list) and click "Add user" to save it. I see a spinner next to Cancel button for 1-2 seconds and nothing happens.
I then went to Users, clicked the desired user and then "Add Group" button. I searched "site-admins" group but again it would not let me add it. I see the spinner for 1-2 seconds and nothing happens. There is no error message shown either.