[SOLVED] Fed 23 (KDE) Apps suddenly lost titlebars, desktop lost gkrellm

Hello!

I suddenly lost titlebars of all applications, which means:
I can't move/resize windows, can't raise windows by clicking on
part of them protruding from below the topmost window.
Also, I have "gkrellm" monitors started automatically after login,
during login I see "gkrellm" for 2-3 seconds and suddenly
it disappears from the desktop (but I still see it in "top").
Also, the panel with shortcuts suddenly became much shorter and I can't
find a way to make it occupying the whole width of the screen.
For some time I also thought that I lost keyboard input to GUI apps (konsole
worked OK) and thought I can't even write this post because I couldn't
type anything in the username/password fields of this site. But after
"copy/paste" from konsole I regained the ability to type in GUI (at least, Firefox
where I'm writing now).

This all happened on the next shutdown and reboot after I changed Desktop theme.
I thought that by clicking "apply" I'll see everything that changed (I searched to
make icons text bright) and indeed changing theme changed text colot) but maybe theme
change ruined something?

I attempted to select the previous theme but this didn't help.

How can I debug this problem?
At what files should Ilook?

I can open konsole and editor, not sure if I could write something in the editor.

TIA,
kaza.

Some more info: I just played a video clip with Firefox and I noticed that:

1) Clicking the "full screen" icon has no effect.
2) The video plays but the secods counter remains on zero
and the progress bar remains of zero length.
3) Clicking the "pause/play" icon has the correct effect
but the icon remains "pause", it doesn't change from "pause"
to "play" and back when I click on it.

All this are new phenomena, immediately after Fedora 23 everything
worked OK.

Did I ruined the whole KDE session?

BTW, I remembered that between changing desktop theme
and shutting down (after which the problems started),
I played with "FlightGear". Can it do some damage?

Is there any way to restore to "immediately after installation" session?

As a last resort I can reinstall again (my "/home" is on separate
partition so I don't have to wipe it and re-create. I also made
2 backups to tape of the entire system) but before going this way
I would like to know if there is a simple solution.

TIA for any ideas,
kaza.

Decided to "byte the bullet" and reinstalled FC23 again.
So far so good. Changed in "startup and shutdown" to use "manually saved session".
While installinh additional RPMs (I saved "rpm -qa"from previous stable setup of FC19,
crated "diff" and manually added things I need not installed by default) had few ocasions
that on boot desktop icons "forgot" their locations and lined in a line from top left
corner and I had to manually re-arrange them the way I like. Will see if stays stable.