[15.4] plasma session will not start: klauncher & ksplashqml segfault

Instead of Plasma session starting from the greeter, or using startx,
two popup windows result:
first: klauncher closed unexpectedly (segmentation fault)
after some wait: ksplashqml closed unexpectedly (segmentation fault)

# cat .xsession-errors
Environment variable $XAUTHORITY not set, ignoring.
/etc/X11/xim: Checking whether an input method should be started.
sourcing /etc/sysconfig/language to get the value of INPUT_METHOD
INPUT_METHOD is not set or empty (no user selected input method).
Trying to start a default input method for the locale en_US.UTF-8 ...
There is no default input method for the current locale.
Dummy input method "none" (do not use any fancy input method by default)
gpg-connect-agent: no gpg-agent running in this session
gpg-connect-agent: no gpg-agent running in this session
KCrash: Application 'ksplashqml' crashing...
KCrash: Attempting to start /usr/lib64/libexec/drkonqi
KCrash: Application 'klauncher' crashing...
kdeinit5: Communication error with launcher. Exiting!
KCrash: Attempting to start /usr/lib64/libexec/drkonqi
KCrash: Application 'org_kde_powerdevil' crashing...
KCrash: Attempting to start /usr/lib64/libexec/drkonqi
Unable to start Dr. Konqi
Re-raising signal for core dump handling.
Unable to start Dr. Konqi
Re-raising signal for core dump handling.
kwin: unable to claim manager selection, another wm running? (try using --replace)

[code]# zypper rm --clean-deps plasma5-workspace-libs plasma5-workspace plasma5-session plasma-framework libKF5Plasma5 libKF5Purpose5 libKF5Plasma5 libKF5Declarative5 libKF5Runner5
# zypper rm --clean-deps libKF5Solid5 libKF5DBusAddons5 libKF5CoreAddons5 libKF5WidgetsAddons5 libKF5WindowSystem5 libKF5XmlGui5
# zypper -v in plasma5-workspace plasma5-session systemsettings5[/code]

Over 200 packages were removed, and 211 installed, but this failed
to solve the problem - twice. I searched the whole /usr/ filesystem
tree looking for *launche*, before and after the reinstallations, and
could not find klauncher (actually, nothing was returned from searching
for *launch*).

IceWM sessions work normally, so there can't be anything wrong with Xorg.

TDE sessions open normally, but are peppered by a continuous series of
popups generated by kglobalaccel5, unless I reboot after attempting to
open a Plasma session, in which case it produces the following:
# inxi -SMCz
System:
  Host: ara88 Kernel: 5.14.21-150400.22-default arch: x86_64 bits: 64
    Desktop: Trinity v: R14.0.12 Distro: openSUSE Leap 15.4
Machine:
  Type: Desktop Mobo: ASRock model: FM2A88X Extreme6+ serial: <filter>
    UEFI: American Megatrends v: P4.20 date: 01/13/2016
CPU:
  Info: quad core model: AMD PRO A8-8650B R7 10 Compute Cores 4C+6G bits: 64
    type: MT MCP cache: L2: 4 MiB
  Speed (MHz): avg: 1400 min/max: 1400/3200 cores: 1: 1400 2: 1400 3: 1400
    4: 1400
# inxi -Gaz
Graphics:
  Device-1: AMD Kaveri [Radeon R7 Graphics] vendor: ASRock driver: amdgpu
    v: kernel alternate: radeon arch: GCN 2 process: GF/TSMC 16-28nm
    built: 2013-17 ports: active: DP-1,DVI-D-1,HDMI-A-1 empty: VGA-1
    bus-ID: 00:01.0 chip-ID: 1002:1313 class-ID: 0300
  Display: x11 server: X.Org v: 1.20.3 driver: X: loaded: modesetting
    gpu: amdgpu display-ID: :0 screens: 1
  Screen-1: 0 s-res: 2560x3720 s-dpi: 120 s-size: 541x787mm (21.30x30.98")
    s-diag: 955mm (37.6")
  Monitor-1: DP-1 pos: primary,bottom model: Acer K272HUL serial: <filter>
    built: 2018 res: 2560x1440 hz: 60 dpi: 109 gamma: 1.2
    size: 598x336mm (23.54x13.23") diag: 686mm (27") ratio: 16:9 modes:
    max: 2560x1440 min: 720x400
  Monitor-2: DVI-D-1 pos: middle model: NEC EA243WM serial: <filter>
    built: 2011 res: 1920x1200 hz: 60 dpi: 94 gamma: 1.2
    size: 519x324mm (20.43x12.76") diag: 612mm (24.1") ratio: 16:10 modes:
    max: 1920x1200 min: 640x480
  Monitor-3: HDMI-A-1 mapped: HDMI-1 pos: primary,top model: Samsung
    built: 2009 res: 1920x1080 hz: 60 dpi: 305 gamma: 1.2
    size: 160x90mm (6.3x3.54") diag: 184mm (7.2") ratio: 16:9 modes:
    max: 1920x1080 min: 720x400
  OpenGL:
    renderer: AMD KAVERI (DRM 3.42.0 5.14.21-150400.22-default LLVM 11.0.1)
    v: 4.6 Mesa 21.2.4 direct render: Yes

Wiping out ~/.cache/* and KDE/Plasma files/directories in ~/.config/ helped
none AFAICT.

# ps -A (tail; while running a TDE session, following a Plasma session attempt)
  919 ?        00:00:00 (sd-pam)
  960 ?        00:00:00 dbus-daemon
 1041 ?        00:00:00 kwin_x11
 1074 ?        00:00:00 ksmserver
 1253 ?        00:00:00 dconf-service
 1345 ?        00:00:00 dcopserver
 1353 ?        00:00:00 in.telnetd
 1354 ?        00:00:00 login
 1355 pts/0    00:00:00 bash
 1441 ?        00:00:00 systemd-localed
 1446 ?        00:00:00 tdm
 1448 tty7     00:00:01 X
 1463 ?        00:00:00 tdm
 1464 ?        00:00:00 tdm_greet
 1465 ?        00:00:00 tdekbdledsync
 1470 ?        00:00:00 krootimage
 1473 ?        00:00:00 twin
 1475 ?        00:00:00 dcopserver
 1485 ?        00:00:00 udisksd
 1489 ?        00:00:00 polkitd
 1500 ?        00:00:00 systemd-udevd
 1569 pts/0    00:00:00 ps

Journal from fresh boot, then attempting to start Plasma:
https://paste.opensuse.org/50832894

PC is multiboot with 15.3, in which Plasma works normally, and from
which a clone was made and upgraded to create this 15.4 before its
final release.

Where do I look to find the root of this problem, particularly the
location of crashers klauncher & ksplashqml, to find out what rpms
provide them?
-- 
Evolution as taught in public schools is, like religion,
	based on faith, not based on science.

 Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!

Felix Miata