KWin frequent crashes after upgrade to Plasma 5.3

[Torsten Römer]

After upgrading kubuntu 15.04 to Plasma 5.3 from the backports PPA, KWin crashes in rapid succession and I get a dialog (translated from German) "KWin is unstable. It seems it crashed multiple times in a row. You can choose another window manager:"
The dropdown however only offers "kwin_x11".

Please see the attached backtrace, hope it is useful.

Most of the time, the startup screen hangs forever at about 80%. Switching to a console and "killall startkde" and trying to log in again sometimes goes further, and then the KWin crashes occur.

[Torsten Römer (dode)]

Please ignore/delete this bug report. The upgrade was incomplete, some packages were held back. After several more attempts to "apt-get update" and "apt-get upgrade", eventually the remaining packages were installed and now all is fine.

Sorry for that!

[Jasem Mutlaq (mutlaqja)]

I encountered the same issue so I would like to help other who might face the same issue. I added Kubuntu backports PPA, run 'sudo apt-get update && sudo apt-get upgrade' and after all is done, I simply assumed everything was installed and rebooted. I spent the next two hours trying to figure out why kwin keeps crashing and Plasma became TOTALLY unusable.

After I ran 'sudo apt-get upgrade' again, I got a list of packages that were 'kept back', i.e. not installed, so I installed them one by one to see if there was any conflicts with others repo...etc and after all the proper packages were installed, Plasma worked fine!

[Flames_in_Paradise (ellisistfroh-deactivatedaccount)]

So well, in cas u installed some packages and "kubuntu-desktop" was uninstalled – it would need a reinstall definetly to be in coherence with the backports.ppa, essentialy. The meta-package would drag in any missing files.

Thanks for reporting & happy kubuntuing

[Flames_in_Paradise (ellisistfroh-deactivatedaccount)]

corr.: So well, in case u uninstalled some packages and "kubuntu-desktop" was accordingly uninstalled – ...