Launching ANY Application [except Google Chrome] crashes Plasma Desktop

[CAaronL]

Help!

I have a shiny new Kubuntu 13.10 installation that is only a few weeks old, and I apparently have some kind of corruption in my home (.kde, perhaps?) directory....

Randomly, after a "sudo apt-get dist-upgrade" that just upgraded some random libraries that didn't seem that critical, now whenever I launch any application at all, it crashes my plasma-desktop. The wallpaper/widgets/panels all disappear, the screen goes black, and then, slowly, plasma-desktop restarts and everything comes back. It is a major annoyance because it happens whenever I launch any application, whether it be from an application menu, via ALT-F2, or via the command line.

One thing that I've noticed is that if I start a program as superuser (e.g., "sudo dolphin"), everything is fine and the desktop doesn't crash. It's obviously extremely undesirable to launch every program as a superuser, however.

Oh, and, randomly -- Google Chrome seems to be the one application that will launch without creating a problem with the plasma-desktop module. It starts right up and my wallpaper/widgets/etc. all stay intact.

I do have the Kubuntu Beta, Backport, and Updates PPAs enabled. I thought maybe that was the issue, so I used PPA-Purge to remove those PPAs and revert back to standard packages, but it didn't correct the error. Since then, I have gone ahead and re-enabled the repos and updated/upgraded.

I don't know where to start to figure out what is causing this issue. I know I could just remove my whole .kde directory and start over from scratch, but i really want to avoid that option except as a very last resort. I have spent a lot of time customizing and setting up my KDE installation, and I don't want to have to do that all over again.

Anyone have any suggestions?

[jlittle]

... e.g., "sudo dolphin"

Well, there's a problem already. You shouldn't start gui progams with sudo; doing so causes various problems, including the one you report, by making files in your home directory owned by root. Use kdesudo instead.
To fix the file ownership, press ctrl-alt-f1 to get a linux console and log in, and run

sudo chown -R user:user .

substituting user with your username (twice). Log out and press ctrl-alt-f7 to get back to KDE.

Regards, John Little

[CAaronL]

Thanks for your reply.

I should have specified -- I don't normally start applications as root in this way. When the Plasma Desktop started crashing, I suspected it might be a permissions/ownership issue, so I tried starting dolphin via "sudo dolphin," and found it did start without crashing Plasma.

I had actually tried adjusting all file permissions, using Dolphin's GUI rather than via a separate terminal login, but I tried it using your method as well. No dice. I still have the same problem I had before. What next?

[jlittle]

All I can suggest is moving plasma config files to one side, having logged out of KDE. You might start with the slightly drastic
mv .kde .kde-old
(from a linux console, as in my first post, having logged out of KDE, then login to KDE), to bracket the problem. If you want sundry KDE settings back:
rm -r .kde
mv .kde-old .kde

If the problem went away (but lost lots of settings that you wanted back), then I see these in my Saucy .kde that might be relevant:
.kde/share/config/plasma-desktoprc
.kde/share/config/plasma-desktop-appletsrc
.kde/share/config/plasmarc
and the .kde/share/apps/plasma directory. Either delete them, or move them aside.

HTH, and regards, John Little

[CAaronL]

After hours and hours of pulling my hair out over this issue, I wanted to include an update as to how it was fixed.

It turns out the culprit was the "Smooth Tasks" widget. Finally after crashing applications left and right, I got a KDE error message which told me that plasma-desktop had crashed do to a "segmentation fault." When I clicked on the option for more detailed information, I noticed "plasma-widget-smooth-tasks" mentioned a couple of times in the many lines of gobbledegook. That seemed odd to me, so I removed the Smooth Tasks widget from the panel, and the random crashes immediately stopped happening.

It still seems weird to me, because I wasn't launching applications using the Smooth Tasks widget in any way. I was launching them either using the Application Menu or KRunner. But just having Smooth Tasks running at all seems to have caused a problem -- it must have had something to do with adding them to the taskbar after they were launched.

Anyway, thank you for all your advice! Glad to get to the bottom of this.

[kubicle]

it must have had something to do with adding them to the taskbar after they were launched.

You are correct.

The crash of the smooth tasks widget (a widget crash takes the plasma desktop with it) is likely caused by the fact that the version of smooth task you have installed is built against older, incompatible versions of kdelibs (libtaskmanager). This can happen if you upgrade kde from the ppas, some "3rd party widget" packages may be incompatible.