Hello. The solution was already posted in French so I just try to translate here:
It’s a bug. While waiting for the update it is solvable by modifying the following file: /usr/lib/python3/dist-packages/wazo_ui/plugins/user/view.py
And line 299 of the view.py file you have to modify this:
if line['registrar']:
To this:
if line.get('registrar'):
Then you have to reboot the machine.