Legitimation request starts with disabled password field

[dronus]

After upgrading Ubuntu from 14.04.3 to 16.04.1, every legitimation request (eg. from update-manager) shows a greyed-out password box.

However, if I use the user dropdown to switch to another user, the password field gets enabled. It stays enabled if I switch back to my own user. I can enter the password then and it is accepted as intended.

Hint: As I use a gnome-flashback session, the bug may have to do with focus management. I noticed that the legitimation request password box is greyed out if the window openes without focus.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Jacek Kluza (jacek-kluza+ubuntu1)]

Same here. I use a gnome-flashback session too, I use the user dropdown to switch to another user, too.