notifications don't go away

[Dan Keshet]

When I get notifications, they remain, permanently, even after the event has been resolved. They persist through ending the session and beginning again, although not through a reboot. The example I have attached is a system update available notification, but earlier, I had different notifications. Hovering over them makes them transparent but doesn't reveal a way to remove. The notification menu in the system tray says there are notifications.

dkesh@bran:~$ lsb_release -rd
Description: Ubuntu 15.04
Release: 15.04

dkesh@bran:~$ apt-cache policy kubuntu-desktop
kubuntu-desktop:
  Installed: 1.323
  Candidate: 1.323
  Version table:
 *** 1.323 0
        500 http://us.archive.ubuntu.com/ubuntu/ vivid/universe amd64 Packages
        100 /var/lib/dpkg/status

[erugg (eru-gg)]

Confirmed.

Particularly, in my case notifications about Wi-Fi don't fade away (losing connection, succesful connection, 'can't scan while already scanning')

Temporary solution - restart plasma:
Alt+F2
killall plasmashell
plasmashell

Then the notifications 'catch up', i.e. the ones that should have appeared after the one which was stuck, appear for a brief moment and the fade away normally

[Launchpad Janitor (janitor)]

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

[Ales (w-ales)]

In my case it's "System update available" only. When it show up it persist forever. Other notifications behave as expected.

[Dan Keshet (dan-keshet)]

This could be a total red herring, but I've been experiencing this mostly after I have plugged an external monitor in to my laptop (in side-by-side mode) and then removed that external monitor.

[Tobias Schmidt (tobias-schmidt403+launchpad)]

I mainly experience this issue after waking up the system from stand by. Usually it's a notification about "available updates", but it can be others too.

The killall plasmashell command does help sometimes, but often it does not and then I have no clue how to remove this annoying notification (except for rebooting the system).

Until there is a fix: Is there any way to remove notifications "manually"?