KDE plasma 5: no taskbar and can't right click desktop

Question

No idea how this happened. plasmashell was crashing after consuming 6gb memory and I'd tried removing ~/.cache. Shortly after all plasmashell would do is start my desktop background with a wallpaper but wouldn't give me any taskbar and I couldn't bring up a menu by right clicking the desktop.

Restarting it or rebooting the whole machine didn't help.

Answer 1

jozxyqk's answer is correct, but it is fairly drastic. It will blow away all of your toolbar customizations, app favorites , etc.

Depending on the cause of this issue in your case, you may be able to fix it by editing your plasma-org.kde.plasma.desktop-appletsrc file and then performing

kquitapp plasmashell && kstart plasmashell

One cause I've run into is the buggy multimonitor functionality sometimes "losing" the taskbar from my laptop screen after I've connected to an external monitor and later disconnected (this was in plasma 5.5 or 5.6, I think). In this scenario, I've found the problem to be the lastScreen setting in the taskbar configuration. To fix this, find the section of text in plasma-org.kde.plasma.desktop-appletsrc that looks like:

[Containments][1]
activityId=
formfactor=2
immutability=1
lastScreen=1
location=4
plugin=org.kde.panel
wallpaperplugin=org.kde.image

(Some of these lines may vary in your configuration. In mine, this section was only a dozen lines down in the file, but I have no idea how much that may vary.)

Setting lastscreen=0 fixed the problem for me. I assume that 0 represents my laptop screen, and 1 is the external monitor.

If in doubt, you can always perform the procedure in jozxyqk's answer, and compare the newly generated plasma-org.kde.plasma.desktop-appletsrc with your saved plasma-org.kde.plasma.desktop-appletsrc.bak before restoring an edited version of your saved copy.

Answer 2

Update: Please see EricS's answer first as you may be able to avoid losing your KDE config.

---

I ended up removing random config files with the name plasma in them. The one that worked was:

cd ~/.config
mv plasma-org.kde.plasma.desktop-appletsrc \
   plasma-org.kde.plasma.desktop-appletsrc.bak

Then restart plasmashell:

kbuildsycoca5 && kquitapp plasmashell && kstart plasmashell

Answer 3

I have also found this condition occurring when a plasma-org.kde.plasma.desktop-appletsrc.lock file is left in the ~/.config directory. Removing the lock file cleared the problem immediately.

Answer 4

In my case with KDE 5.8.8 removing the following two config files helped:

rm ~/.config/plasma-org.kde.plasma.desktop-appletsrc
rm ~/.config/plasmashellrc

Then starting KDE again.

For some reason, default widgets like taskbar were not configured on initial setup during some upgrades etc.

Answer 5

Edit plasma-appletsrc and delete this section.

[PlasmaViews][Panel 46][Horizontal1600]
alignment=132
maxLength=1600
minLength=1600
offset=0
panelVisibility=0
thickness=36

Then reboot.