Comment # 2 on bug 1123058 from Bernhard Dr. Friedrichs

I use zypper dup ONLY
Same happened last year - so it is the second time for me.
The following zypper dup 5 days later solved the problem
(so long I was booting the previous kernel)

Follows /var/log/Xorg.0.log:

[    20.849] (--) Log file renamed from "/var/log/Xorg.pid-2854.log" to
"/var/log/Xorg.0.log"
[    20.850] 
X.Org X Server 1.20.3
X Protocol Version 11, Revision 0
[    20.850] Build Operating System: openSUSE SUSE LINUX
[    20.850] Current Operating System: Linux isimaster 4.20.0-1-default #1 SMP
PREEMPT Tue Jan 8 08:38:29 UTC 2019 (34f009a) x86_64
[    20.850] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-4.20.0-1-default
root=UUID=c9fbb9de-6d8f-4242-ba9e-d3a8561ee771 quiet
resume=/dev/disk/by-uuid/dda9c8d7-257b-4b7e-b8af-c85a91cc9762 splash=silent
quiet showopts usbcore.autosuspend=-1
[    20.850] Build Date: 02 January 2019  12:00:00PM
[    20.850]  
[    20.850] Current version of pixman: 0.36.0
[    20.850]     Before reporting problems, check http://wiki.x.org
    to make sure that you have the latest version.
[    20.850] Markers: (--) probed, (**) from config file, (==) default setting,
    (++) from command line, (!!) notice, (II) informational,
    (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[    20.850] (==) Log file: "/var/log/Xorg.0.log", Time: Thu Jan 24 19:06:48
2019
[    20.850] (==) Using config file: "/etc/X11/xorg.conf"
[    20.850] (==) Using config directory: "/etc/X11/xorg.conf.d"
[    20.850] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[    20.852] (==) ServerLayout "Layout0"
[    20.852] (**) |-->Screen "Screen0" (0)
[    20.852] (**) |   |-->Monitor "Monitor0"
[    20.852] (**) |   |-->Device "Device0"
[    20.852] (**) |-->Input Device "Keyboard0"
[    20.852] (**) |-->Input Device "Mouse0"
[    20.852] (**) Option "Xinerama" "0"
[    20.852] (==) Automatically adding devices
[    20.852] (==) Automatically enabling devices
[    20.852] (==) Automatically adding GPU devices
[    20.852] (==) Max clients allowed: 256, resource mask: 0x1fffff
[    20.855] (WW) The directory "/usr/share/fonts/misc/sgi" does not exist.
[    20.855]     Entry deleted from font path.
[    20.855] (==) FontPath set to:
    /usr/share/fonts/misc:unscaled,
    /usr/share/fonts/Type1/,
    /usr/share/fonts/100dpi:unscaled,
    /usr/share/fonts/75dpi:unscaled,
    /usr/share/fonts/ghostscript/,
    /usr/share/fonts/cyrillic:unscaled,
    /usr/share/fonts/truetype/,
    built-ins
[    20.855] (==) ModulePath set to "/usr/lib64/xorg/modules"
[    20.855] (WW) Ignoring unrecognized extension "XFree86-DGA"
[    20.855] (WW) Hotplugging is on, devices using drivers 'kbd', 'mouse' or
'vmmouse' will be disabled.
[    20.855] (WW) Disabling Keyboard0
[    20.855] (WW) Disabling Mouse0
[    20.855] (II) Loader magic: 0x5593663d1d00
[    20.855] (II) Module ABI versions:
[    20.855]     X.Org ANSI C Emulation: 0.4
[    20.855]     X.Org Video Driver: 24.0
[    20.855]     X.Org XInput driver : 24.1
[    20.855]     X.Org Server Extension : 10.0
[    20.857] (++) using VT number 7

[    20.857] (II) systemd-logind: logind integration requires -keeptty and
-keeptty was not provided, disabling logind integration
[    20.862] (--) PCI:*(36@0:0:0) 10de:1d01:1462:8c98 rev 161, Mem @
0xfc000000/16777216, 0xe0000000/268435456, 0xf0000000/33554432, I/O @
0x0000e000/128, BIOS @ 0x????????/524288
[    20.862] (II) LoadModule: "glx"
[    20.863] (II) Loading /usr/lib64/xorg/modules/extensions/libglx.so
[    20.887] (II) Module glx: vendor="NVIDIA Corporation"
[    20.887]     compiled for 4.0.2, module version = 1.0.0
[    20.887]     Module class: X.Org Server Extension
[    20.888] (II) NVIDIA GLX Module  390.87  Tue Aug 21 16:10:56 PDT 2018
[    20.888] (II) LoadModule: "nvidia"
[    20.889] (II) Loading /usr/lib64/xorg/modules/drivers/nvidia_drv.so
[    20.894] (II) Module nvidia: vendor="NVIDIA Corporation"
[    20.894]     compiled for 4.0.2, module version = 1.0.0
[    20.894]     Module class: X.Org Video Driver
[    20.894] (II) NVIDIA dlloader X Driver  390.87  Tue Aug 21 15:44:49 PDT
2018
[    20.894] (II) NVIDIA Unified Driver for all Supported NVIDIA GPUs
[    20.938] (II) Loading sub module "fb"
[    20.938] (II) LoadModule: "fb"
[    20.939] (II) Loading /usr/lib64/xorg/modules/libfb.so
[    20.939] (II) Module fb: vendor="X.Org Foundation"
[    20.939]     compiled for 1.20.3, module version = 1.0.0
[    20.939]     ABI class: X.Org ANSI C Emulation, version 0.4
[    20.939] (II) Loading sub module "wfb"
[    20.939] (II) LoadModule: "wfb"
[    20.940] (II) Loading /usr/lib64/xorg/modules/libwfb.so
[    20.941] (II) Module wfb: vendor="X.Org Foundation"
[    20.941]     compiled for 1.20.3, module version = 1.0.0
[    20.941]     ABI class: X.Org ANSI C Emulation, version 0.4
[    20.941] (II) Loading sub module "ramdac"
[    20.941] (II) LoadModule: "ramdac"
[    20.941] (II) Module "ramdac" already built-in
[    20.949] (EE) NVIDIA: Failed to initialize the NVIDIA kernel module. Please
see the
[    20.949] (EE) NVIDIA:     system's kernel log for additional error messages
and
[    20.949] (EE) NVIDIA:     consult the NVIDIA README for details.
[    20.949] (EE) No devices detected.
[    20.949] (EE) 
Fatal server error:
[    20.949] (EE) no screens found(EE) 
[    20.949] (EE) 
Please consult the The X.Org Foundation support 
     at http://wiki.x.org
 for help. 
[    20.949] (EE) Please also check the log file at "/var/log/Xorg.0.log" for
additional information.
[    20.949] (EE) 
[    21.038] (EE) Server terminated with error (1). Closing log file.