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

X.Org X Server 1.20.10
X Protocol Version 11, Revision 0
Build Operating System: linux Ubuntu
Current Operating System: Linux xubuntu 5.11.0-14-generic #15-Ubuntu SMP Thu Apr 8 21:39:23 UTC 2021 x86_64
Kernel command line: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/xubuntu.seed maybe-ubiquity quiet splash ---
Build Date: 09 April 2021  10:30:53AM
xorg-server 2:1.20.10-3ubuntu7 (For technical support please see http://www.ubuntu.com/support) 
Current version of pixman: 0.40.0
	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: Mon Apr 19 09:30:26 2021
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
(II) [KMS] Kernel modesetting enabled.
resizing primary to 1024x768
primary is 0x5631d07ee120
ubiquity-dm: set vars
ubiquity-dm: pam_open_session
ubiquity-dm: dm-scripts
ubiquity-dm: start frontend gtk_ui
No such schema “org.gnome.settings-daemon.plugins.background”
No such schema “org.gnome.metacity”
ubiquity-dm: start greeter

(xfsettingsd:1510): GLib-CRITICAL **: 09:30:31.370: g_str_has_prefix: assertion 'prefix != NULL' failed

(xfsettingsd:1510): GLib-GObject-CRITICAL **: 09:30:31.387: g_value_get_string: assertion 'G_VALUE_HOLDS_STRING (value)' failed

(xfsettingsd:1510): GLib-GObject-CRITICAL **: 09:30:31.470: g_value_get_string: assertion 'G_VALUE_HOLDS_STRING (value)' failed

(xfsettingsd:1510): GLib-GObject-CRITICAL **: 09:30:31.488: g_value_get_string: assertion 'G_VALUE_HOLDS_STRING (value)' failed

(xfwm4:1508): GLib-CRITICAL **: 09:30:35.351: g_str_has_prefix: assertion 'prefix != NULL' failed