Xorg crashed with SIGABRT in OsAbort()

[Knarf]

in /etc/gdm3/custom.conf

wayland=false

adjusted

and in gdm3 goes xorg.

but lightdm is better.

ProblemType: Crash
DistroRelease: Ubuntu 18.04
Package: xserver-xorg-core 2:1.19.6-1ubuntu2
ProcVersionSignature: Ubuntu 4.15.0-11.12-generic 4.15.5
Uname: Linux 4.15.0-10-generic x86_64
ApportVersion: 2.20.8-0ubuntu10
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
CurrentDesktop: GNOME-Greeter:GNOME
Date: Mon Feb 26 19:04:05 2018
DistUpgraded: 2017-12-04 01:28:38,355 ERROR got error from PostInstallScript ./xorg_fix_proprietary.py (g-exec-error-quark: Kindprozess »./xorg_fix_proprietary.py« konnte nicht ausgeführt werden (Datei oder Verzeichnis nicht gefunden) (8))
DistroCodename: bionic
DistroVariant: ubuntu
ExecutablePath: /usr/lib/xorg/Xorg
ExtraDebuggingInterest: Yes
GraphicsCard:
 Advanced Micro Devices, Inc. [AMD/ATI] Turks PRO [Radeon HD 6570/7570/8550] [1002:6759] (prog-if 00 [VGA controller])
   Subsystem: PC Partner Limited / Sapphire Technology Turks PRO [Radeon HD 6570/7570/8550] [174b:e193]
JournalErrors:
 -- Logs begin at Wed 2017-12-13 16:49:59 CET, end at Mon 2018-02-26 19:12:42 CET. --
 Feb 26 19:09:32 hostname wpa_supplicant[951]: dbus: wpa_dbus_get_object_properties: failed to get object properties: (none) none
 Feb 26 19:09:32 hostname wpa_supplicant[951]: dbus: Failed to construct signal
 Feb 26 19:11:08 hostname pulseaudio[1908]: [pulseaudio] bluez5-util.c: GetManagedObjects() failed: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
MachineType: MSI MS-7850
ProcCmdline: /usr/lib/xorg/Xorg vt1 -displayfd 3 -auth /run/user/122/gdm/Xauthority -background none -noreset -keeptty -verbose 7 -core
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/false
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-11-generic root=UUID=b2e8def1-dfe2-48ba-abf5-0431a8a4d85c ro vesafb.invalid=1
Signal: 6
SourcePackage: xorg-server
StacktraceTop:
 OsAbort ()
 ?? ()
 FatalError ()
 xf86VTLeave ()
 WakeupHandler ()
Title: Xorg crashed with SIGABRT in OsAbort()
UpgradeStatus: Upgraded to bionic on 2017-12-04 (84 days ago)
UserGroups:

dmi.bios.date: 03/30/2015
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: V2.9
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: B85-G41 PC Mate(MS-7850)
dmi.board.vendor: MSI
dmi.board.version: 1.0
dmi.chassis.asset.tag: To be filled by O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: MSI
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrV2.9:bd03/30/2015:svnMSI:pnMS-7850:pvr1.0:rvnMSI:rnB85-G41PCMate(MS-7850):rvr1.0:cvnMSI:ct3:cvr1.0:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: MS-7850
dmi.product.version: 1.0
dmi.sys.vendor: MSI
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.90-1
version.libgl1-mesa-dri: libgl1-mesa-dri 18.0.0~rc4-1ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx 18.0.0~rc4-1ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.19.6-1ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.10.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20171229-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-2
xserver.bootTime: Mon Feb 26 19:00:25 2018
xserver.configfile: default
xserver.devices:
 input Power Button KEYBOARD, id 6
 input Power Button KEYBOARD, id 7
 input AT Translated Set 2 keyboard KEYBOARD, id 8
 input ImPS/2 Logitech Wheel Mouse MOUSE, id 9
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.19.6-1ubuntu2
xserver.video_driver: radeon

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #1710354, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.