ubiquity-dm: starting
ubiquity-dm: plymouth
ubiquity-dm: start X ['X', '-br', '-ac', '-noreset', '-nolisten', 'tcp', '-background', 'none', 'vt1', ':0']

X.Org X Server 1.20.4
X Protocol Version 11, Revision 0
Build Operating System: Linux 4.4.0-143-generic x86_64 Ubuntu
Current Operating System: Linux ubuntu 5.0.0-13-generic #14-Ubuntu SMP Mon Apr 15 14:59:14 UTC 2019 x86_64
Kernel command line: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity quiet splash ---
Build Date: 03 April 2019  09:03:57AM
xorg-server 2:1.20.4-1ubuntu3 (For technical support please see http://www.ubuntu.com/support) 
Current version of pixman: 0.36.0
	Before reporting problems, check http://wiki.x.org
	to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
	(++) from command line, (!!) notice, (II) informational,
	(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Sat Sep  7 13:20:57 2019
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
(EE) 
Fatal server error:
(EE) Server is already active for display 0
	If this server is no longer running, remove /tmp/.X0-lock
	and start again.
(EE) 
(EE) 
Please consult the The X.Org Foundation support 
	 at http://wiki.x.org
 for help. 
(EE) 
(EE) 
Fatal server error:
(EE) Server is already active for display 0
	If this server is no longer running, remove /tmp/.X0-lock
	and start again.
(EE) 
(EE) 
Please consult the The X.Org Foundation support 
	 at http://wiki.x.org
 for help. 
(EE) 
(II) modeset(0): Initializing kms color map for depth 24, 8 bpc.
ubiquity-dm: Failed with an exception:
ubiquity-dm: Traceback (most recent call last):
  File "/usr/bin/ubiquity-dm", line 882, in main
    ret = run(vt, display, username)
  File "/usr/bin/ubiquity-dm", line 857, in run
    ret = dm.run(*sys.argv[4:])
  File "/usr/bin/ubiquity-dm", line 351, in run
    'code ' + str(status))
XStartupError: X server exited with return code 1

(II) Server terminated successfully (0). Closing log file.