I'll just toss here a list of problems I have with the recent upgrade to kubuntu 15.04

I'll accept that all my settings are gone because of the change of framework 4 to 5 (it would have been nice to get a big fat warning about it, or better an update/transfer method), but during the upgrade process I was asked if I wanted to keep LightDM or use the new SDDM. I chose the former, but still the latter was installed and causes problems (how do I switch between them ?)

In particular I now cannot unlock a locked screen: after I type my password, it blacks out briefly then comes back to the login screen. I can't start a new session either. After I reboot I get a crash screen about a sddm-greeter crash. Also there's no [Off]/[Reboot] buttons on the login screen.

Once logged in, if I try to log out or reboot I get plenty of crash window for various kde and sddm components and can't cleanly logout/reboot.

Something else very annoying: there's no more console in Ctrl-Alt-F2 and others. Just a black screen. Typing login/passwd blind doesn't work.

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    the " after I type my password, it blacks out briefly then comes back to the login screen" thing is exactly what I'm seeing with stock Ubuntu as reported here: askubuntu.com/questions/613577 – Gabor Apr 28 '15 at 10:02
  • I can log in fine upon boot, but I will try your suggestion of changing the graphic driver. FWIW I'm using AMD. – dargaud Apr 28 '15 at 14:47

I switched from fglrx-updates to xserver-xorg-video-ati and it solved both the unlock-able lock screen problem and the blank consoles problem.

  • But now I get a black screen upon wake up... Arghhh... – dargaud Apr 29 '15 at 8:07
  • Could you try my answer here askubuntu.com/q/697529/26246 – user.dz Nov 16 '15 at 9:39
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    I can't try it because I gave up and did a fresh install. I didn't check if multiple DMs were running. I remember asking for LightDM to remain, and was surprised that Sddm was installed instead anyway, so you may be right. – dargaud Nov 17 '15 at 18:35
  • Would you accept your own answer here as it does work for you (partially). – user.dz Nov 17 '15 at 20:45
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    I'd say no as I had to reinstall: remaining problems were too problematic. – dargaud Nov 18 '15 at 8:50

<< But now I get a black screen upon wake up... Arghhh. >>

Me, too. Switching from fglrx to xorg video for my ATI graphics card solved my blank Ctrl-Alt-F1 console screen problem, and restoring a $HOME/.config/plasma-org.kde.plasma.desktop-appletsrc file that wasn't missing 60 lines of "[Containments]" got me a working desktop.

But when I wake up the next morning, after leaving the computer running without user interaction for 6 to 8 hours, the screen is blank, and I have to reboot to get a working screen again. My background cron jobs continued to run just fine, and I cannot find any logged error messages or such that might explain the screen outage.

This is on Kubuntu 15.04 using sddm, x86_64, Vivid Vervet, Desktop PC (always on AC, no battery).


  • Can you try increasing the screen brightness with the keyboard ? – dargaud Jun 5 '15 at 21:15

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