Constantly crash Kubuntu 16.04

Question

I have a fresh installation of Kubuntu 16.04, everything crashes : Konsole, firefox, plasma, few times borders of the windows disappear and there is no way how to control it anymore. I have to ssh from another machine and force reboot..

Tried to reinstall it, same issue again, it is just me or somebody else have the same issue ? Here below the log file :

root@fr2632v3:/var/log# more syslog | tail
May 17 15:57:02 fr2632v3 org.kde.kuiserver[1501]: QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave.
May 17 15:57:02 fr2632v3 org.kde.kuiserver[1501]: QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave.
May 17 15:57:02 fr2632v3 org.kde.KScreen[1501]: kscreen: Primary output changed from KScreen::Output(Id: 638 , Name: "DVI-I-1" ) ( "DVI-I-1" ) to KScreen::Output(Id: 638 , Name: "DVI-I-1" ) ( "DVI-I-1" )
May 17 15:57:02 fr2632v3 org.kde.KScreen[1501]: message repeated 3 times: [ kscreen: Primary output changed from KScreen::Output(Id: 638 , Name: "DVI-I-1" ) ( "DVI-I-1" ) to KScreen::Output(Id: 638 , Name: "DVI-I-1" ) ( "DVI-I-1" )]
May 17 15:57:02 fr2632v3 systemd[1]: Started CUPS Scheduler.
May 17 15:57:02 fr2632v3 org.kde.KScreen[1501]: kscreen: Primary output changed from KScreen::Output(Id: 638 , Name: "DVI-I-1" ) ( "DVI-I-1" ) to KScreen::Output(Id: 638 , Name: "DVI-I-1" ) ( "DVI-I-1" )
May 17 15:57:05 fr2632v3 org.kde.KScreen[1501]: message repeated 35 times: [ kscreen: Primary output changed from KScreen::Output(Id: 638 , Name: "DVI-I-1" ) ( "DVI-I-1" ) to KScreen::Output(Id: 638 , Name: "DVI-I-1" ) ( "DVI-I-1" )]
May 17 15:57:25 fr2632v3 pulseaudio[1706]: [pulseaudio] bluez5-util.c: GetManagedObjects() failed: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
May 17 15:57:29 fr2632v3 org.kde.KScreen[1501]: kscreen: Primary output changed from KScreen::Output(Id: 638 , Name: "DVI-I-1" ) ( "DVI-I-1" ) to KScreen::Output(Id: 638 , Name: "DVI-I-1" ) ( "DVI-I-1" )
May 17 15:57:29 fr2632v3 org.kde.KScreen[1501]: message repeated 15 times: [ kscreen: Primary output changed from KScreen::Output(Id: 638 , Name: "DVI-I-1" ) ( "DVI-I-1" ) to KScreen::Output(Id: 638 , Name: "DVI-I-1" ) ( "DVI-I-1" )]

N.B : I did a checksums of the iso before to install it.

Thanks!

Solution

I had the same problem after I fiddled around with the various themes. Especially the 'plastic' window decoration froze the entire desktop. Selecting the default 'breeze' theme seems to have solved it.

On a related note: when the desktop freezes, one can just kill the x-server by pressing Ctrl+Alt+Backspace (provided the option is set in System Settings --> Keyboard --> Advanced --> Key sequence to kill the x-server). So no need to force a reboot.

Comments

[Patrick B.]

In a comment below you mention a downgrade of the NVIDIA drivers, did it help? Have you found out what was the problem of your crashes?

[rf2632]

Hi Patrick, I did run a few test and basically when I tried to upgrade to the NVIDIA latest version (the 361.45.11) it looks stable now...

[FlyBy]

I have pretty much the same problem here using a fresh installation of Ubuntu Mate 16.04 LTS. Looks like it has to do something using the propietary NVidia drivers. The bad thing is, that my monitors do not get recognized correctly without those drivers.

[pbhj]

I've had something similar when trying to use lightdm instead of sddm. Might be worth sudo apt-get remove --purge lightdm* and then install sddm (again).

[chris stevens]

this seems to be kwin crashing - it happens to me a few times a day - I lose all the titlebars and window decorations. It happens usually when opening new windows... But sometimes just clicking the taskbar will stimulate it. alt+F2 then running kwin restarts things and it all works again for a while.... not really a fix tho

[Supernormal]

@rf2632 did downgrading the nvidia driver help for you?