STEPS TO REPRODUCE:
- Login as Admin
- Go to Administer Wiki > User & Rights > Users
- Click 'Add user'
- Fill in the username and password for a new user (e.g. U1)
- Click 'Save'
The new user is created and the page returns to 'Global Administration: Users' where can be seen the list of all users.
When clicking 'Save', a new registration page with blank fields is displayed, identical with the initial 'Registration' lightbox (screenshot attached). However, the new user is created.
The issue reproduces only on Edge browser.