Comment 25 for bug 1605937

A few minutes ago I received an update to wingpanel-indicator-ayatana and wingpanel-indicator-sound. After that I killed wingpanel and restarted it to watch its output:
claas@claas-ThinkPad-T400:~$ sudo killall wingpanel && wingpanel
[INFO 17:54:50.934905] Application.vala:155: Systemleiste version: 2.0.1
[INFO 17:54:50.935099] Application.vala:157: Kernel version: 4.4.0-38-generic
Failed to register: Zeitüberschreitung wurde erreicht
claas@claas-ThinkPad-T400:~$

It means that a timelimit has been reached. Then I repeated thesame command and got:

claas@claas-ThinkPad-T400:~$ sudo killall wingpanel && wingpanel
[INFO 17:55:22.373848] Application.vala:155: Systemleiste version: 2.0.1
[INFO 17:55:22.374042] Application.vala:157: Kernel version: 4.4.0-38-generic
Failed to register: GDBus.Error:org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying
claas@claas-ThinkPad-T400:~$

Perhaps it's helping.