Comment 16 for bug 1525699

I have tried all the options defined up to post #7. I had updated KXStudio version (Kubuntu?) from 14.04 to 16.06. I used the upgrade option listed in muon. All went well until the very last. At that point it crashed and said I now have an unstable system. I restarted and used the new O/S boot rescue. It identified numerous extra packages and numerous missing packages. I allowed it to proceed.

After all this, the KDE logo appeared with loading going on, and then crashed. ctrl alt F7 showed this:
Error Message on mine is:
/scripts/init-premount/plymouth: line 38: /sbin/plymouthd: not found
/scripts/init-premount/plymouth: line 38: /bin/plymouth: not found
Scanning for Btrfs filesystems
KXStudio-1404: recovery journal
KXStudio-1404: clean, 951037/2444624 files, 6343383/9781504 blocks
/scripts/init-bottom/plymouth: line 18/bin/plymouth: not found

1) I the opened tty1 with ctrl alt F1 and logged in. I tried to open X with "xinit" but this failed.
2) I switched to su with "sudo su root" and tried again. This worked. I got a single root xterm on a GUI screen with working mouse.
3) I then entered "kstart plasmashell" and got a full GUI working desktop, but completely devoid of all my applications. This desktop has all GUI windows with out "decorations" (no close, minimize, etc.) and some windows are not movable. Firefox works, but all drop-down menus do not function.
I had some problems getting WiFi to work also, but di it OK after using a wired Ethernet to get Internet help ideas.
4) I tried other combinations and only one other had any effect:
5) As root, I typed "/usr/bin/kde" (which is the contents of /etc/X11/default....)
This gave me a GUI desktop logon screen, but would not actually log me in. It complained about my KDE-plasma ID is no longer valid no matter what I did.
6) I am still experimenting.