I hope this is the right "slot" for my specific bug: I am using Kubuntu 18.04 LTS on an AMD x46 with 8 cores, NVIDIA VGA compatible controller: NVIDIA Corporation GP106 [GeForce GTX 1060 6GB] (rev a1) with proprietary driver v390. I also used the nouveau driver with same result. Maybe it is important for the bug to know that I use two 4K monitors. When i arrange for 4 virtual desktops and switch between the desktops frequently, suddenly all open windows appear on one desktop, and all windows lost their title bar, so I cannot move them anymore. It also is not possible to switch desktops again. Only remedy was so far to reboot until everything started all over again. It seems that I now found the cause (without knowing why): if i disable the "start compositor on system startup" button in "Settings"->Monitors->Compositor the problem does not reappear. I just tried again to turn it on again, and after reboot - voila, I lost the title bars again! Very reproducible... Hope I could help with a constructive bug report - Joe
Sounds like kwin_x11 is crashing. You can confirm this by going to a TTY and running DISPLAY=:0 kwin_x11 You should then see a sad face icon in the system tray which will be useful for fixing the crash.
Created attachment 113649 [details] signature.asc I tried what you suggested but with no effect. The system is asking me if I am using a different window manager (in German, so the wording may be slightly off) Joe Mit freundlichen Grüßen / Yours sincerely, J. Zweck Am / On Freitag, 29. Juni 2018, 17:24:21 CEST schrieben Sie / you wrote: > https://bugs.kde.org/show_bug.cgi?id=396000 > > David Edmundson <kde@davidedmundson.co.uk> changed: > > What |Removed |Added > ---------------------------------------------------------------------------- > CC| |kde@davidedmundson.co.uk Status|UNCONFIRMED > |NEEDSINFO > Resolution|--- |BACKTRACE > > --- Comment #1 from David Edmundson <kde@davidedmundson.co.uk> --- > Sounds like kwin_x11 is crashing. > > You can confirm this by going to a TTY > and running DISPLAY=:0 kwin_x11 > > You should then see a sad face icon in the system tray which will be useful > for fixing the crash.
Created attachment 113650 [details] signature.asc OOps, I got no sad face but the title bars are now gone again - will reboot now. Joe Mit freundlichen Grüßen / Yours sincerely, J. Zweck Am / On Freitag, 29. Juni 2018, 17:24:21 CEST schrieben Sie / you wrote: > https://bugs.kde.org/show_bug.cgi?id=396000 > > David Edmundson <kde@davidedmundson.co.uk> changed: > > What |Removed |Added > ---------------------------------------------------------------------------- > CC| |kde@davidedmundson.co.uk Status|UNCONFIRMED > |NEEDSINFO > Resolution|--- |BACKTRACE > > --- Comment #1 from David Edmundson <kde@davidedmundson.co.uk> --- > Sounds like kwin_x11 is crashing. > > You can confirm this by going to a TTY > and running DISPLAY=:0 kwin_x11 > > You should then see a sad face icon in the system tray which will be useful > for fixing the crash.
I also experience similar kind of bug. Similarly to @Joe Zweck I have a second NVidia card (K1100) in my laptop (Lenovo Thinkpad W541) with proprietary v390 drivers. I also use 4 virtual desktops (if this information is relevant). Before disabling Compositor I was experiencing KWin hangs several times an hour (I've just reinstalled my OS from Kubuntu 16.04 to Kubuntu 18.04.1 from scratch), now it happens once or two times an evening. I should add that during the hang, panel continues to work, i.e., you can e.g. reboot your laptop. I would like to help with more details but I do not see any problems in syslog, maybe there are additional places where I can find relevant information. David Edmundson's suggestion is not working in my case because I cannot run terminal.
A little update to my previous comment. I managed to run terminal through Application Launcher and run the command provided my David. Here is the output in the terminal, however I do not see sad face. ``` QXcbConnection: XCB error: 3 (BadWindow), sequence: 180, resource id: 35651590, major code: 20 (GetProperty), minor code: 0 Module 'org.kde.kwin.decoration' does not contain a module identifier directive - it cannot be protected from external registrations. trying to show an empty dialog QOpenGLContext::swapBuffers() called with non-exposed window, behavior is undefined QOpenGLContext::swapBuffers() called with non-exposed window, behavior is undefined QOpenGLContext::swapBuffers() called with non-exposed window, behavior is undefined QOpenGLContext::swapBuffers() called with non-exposed window, behavior is undefined QOpenGLContext::swapBuffers() called with non-exposed window, behavior is undefined ``` I also need to add that after this command is issued, applications start to respond, however, if you close the terminal they stop responding.
This bug is indeed connected with NVidia (drivers or device). After I used "NVidia X Server Settings" to swith to integrated graphics all the freezes disappeared. I hope this comment is helpful.
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Dear Bug Submitter, This bug has been in NEEDSINFO status with no change for at least 30 days. The bug is now closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging Thank you for helping us make KDE software even better for everyone!