Maybe it's not 6.3.0 related. Maybe it is.
I went back to the image I've done when I installed a brand new 6.0.0, then looked on how all update went via SSH.
Here it is, yes that's some lines

Anyway, all is fine. But that error message is here with 6.3.0, all Pi and all updates I've done.
I've also done a video
https://www.youtube.com/watch?v=VgYIsS9E7Qw so you can see how things go when the Pi reboot. I think it happens now and then when I start but at least each time on each Pi when reboot, never seen before my 6.3.0, or I've missed it before as it pops and vanish just a very start of the UI.
Seems I've reinstalled radios and such... in vain :'( hope we can find what is going on here =)
Code:
Kernel 4.19.64-v7+, Raspbian 10.0, moOde 6.0.0
____ __
__ _ ___ / __ \___/ /__
/ ' \/ _ \/ /_/ / _ / -_)
/_/_/_/\___/\____/\_,_/\__/
moOde audio player
(C) 2014 Tim Curtis
The programs included with Moode are free software; the
exact distribution terms for each program are described
in the individual files in /usr/share/doc/*/copyright.
Moode comes with absolutely no warranties expressed or
implied, or any other guarantees.
Last login: Fri Oct 11 19:55:31 2019 from 192.168.34.11
pi@moode:~ $ moodeutl ?
Usage: moodeutl [OPTION]
Moode utility programs
With no OPTION print the help text and exit.
-i print system info
-l print the moode log
-m run the system monitor
-r restart the servers
-t print last 10 lines of moode log and wait
--version print the program version
--help print this help text
pi@moode:~ $ moodeutl -t
worker: MPD output 4 ALSA graphic eq (off)
20190809 193906 worker: MPD output 5 ALSA polarity inversion (off)
20190809 193906 worker: MPD output 6 ALSA bluetooth (off)
20190809 193906 worker: MPD output 7 HTTP stream (off)
20190809 193906 worker: MPD crossfade (off)
20190809 193906 worker: Audio source (Local)
20190809 193906 worker: Output device (Local)
20190809 193906 worker: - Music sources
20190809 193907 worker: USB sources (none attached)
20190809 193908 worker: NAS and UPnP sources (mountall initiated)
20190809 193908 worker: - Miscellaneous
20190809 193908 worker: Saved MPD vol level (0)
20190809 193908 worker: Preamp volume level (0)
20190809 193908 worker: MPD volume level (0) restored
20190809 193908 worker: ALSA volume level (None)
20190809 193908 worker: Auto-play (Off)
20190809 193908 worker: Maintenance interval (6 hrs)
20190809 193908 worker: Screen saver activation (Never)
20190809 193908 worker: Session permissions (OK)
20190809 193908 worker: Watchdog started
20190809 193908 worker: Ready
20191011 195657 worker: Job installupd
20191011 195657 updater: Downloading update package r600
20191011 195707 updater: Start 2019-08-18 update for moOde 6.0.0
20191011 195707 updater: ** Version check
20191011 195707 updater: ** Step 1-5: SQL updates
20191011 195707 updater: ** Step 2-5: Binary updates
20191011 195707 updater: ** Step 3-5: Code and Config updates
20191011 195710 updater: ** Step 4-5: Linux kernel update
20191011 195846 updater: ** Step 5-5: Syncing changes to disk
20191011 195846 updater: Update installed, REBOOT required
^C
pi@moode:~ $ reboot
Failed to set wall message, ignoring: Interactive authentication required.
Failed to reboot system via logind: Interactive authentication required.
Failed to open initctl fifo: Permission denied
Failed to talk to init daemon.
pi@moode:~ $ Kernel 4.19.66-v7+, Raspbian 10.0, moOde 6.1.0
____ __
__ _ ___ / __ \___/ /__
/ ' \/ _ \/ /_/ / _ / -_)
/_/_/_/\___/\____/\_,_/\__/
moOde audio player
(C) 2014 Tim Curtis
The programs included with Moode are free software; the
exact distribution terms for each program are described
in the individual files in /usr/share/doc/*/copyright.
Moode comes with absolutely no warranties expressed or
implied, or any other guarantees.
Last login: Fri Oct 11 19:56:00 2019 from 192.168.34.11
pi@moode:~ $ moodeutl -t
worker: MPD output 4 ALSA graphic eq (off)
20191011 200027 worker: MPD output 5 ALSA polarity inversion (off)
20191011 200027 worker: MPD output 6 ALSA bluetooth (off)
20191011 200027 worker: MPD output 7 HTTP stream (off)
20191011 200027 worker: MPD crossfade (off)
20191011 200027 worker: Audio source (Local)
20191011 200027 worker: Output device (Local)
20191011 200027 worker: - Music sources
20191011 200027 worker: USB sources (none attached)
20191011 200028 worker: NAS and UPnP sources (mountall initiated)
20191011 200028 worker: - Miscellaneous
20191011 200028 worker: Saved MPD vol level (0)
20191011 200028 worker: Preamp volume level (0)
20191011 200028 worker: MPD volume level (0) restored
20191011 200028 worker: ALSA volume level (None)
20191011 200028 worker: Auto-play (Off)
20191011 200028 worker: Maintenance interval (6 hrs)
20191011 200028 worker: Screen saver activation (Never)
20191011 200028 worker: Session permissions (OK)
20191011 200028 worker: Watchdog started
20191011 200028 worker: Ready
20191011 200201 worker: Job installupd
20191011 200201 updater: Downloading update package r610
20191011 200209 updater: Start 2019-09-05 update for moOde 6.1.0
20191011 200209 updater: ** Version check
20191011 200209 updater: ** Step 1-7: SQL updates
20191011 200210 updater: ** Step 2-7: Radio Station updates
20191011 200210 updater: ** Step 3-7: Package updates
20191011 200210 updater: ** Pkg 1-4: python3-pip
20191011 200339 updater: ** Pkg 2-4: RPi.GPIO
20191011 200353 updater: ** Pkg 3-4: python-musicpd
20191011 200406 updater: ** Pkg 4-4: udevil (includes devmon)
20191011 200417 updater: ** Step 4-7: Binary and Script updates
20191011 200417 updater: ** Step 5-7: Code and Config updates
20191011 200419 updater: ** Step 6-7: Linux kernel update
20191011 200602 updater: ** Step 7-7: Syncing changes to disk
20191011 200602 updater: Update installed, REBOOT required
^C
pi@moode:~ $ reboot
Failed to set wall message, ignoring: Interactive authentication required.
Failed to reboot system via logind: Interactive authentication required.
Failed to open initctl fifo: Permission denied
Failed to talk to init daemon.
pi@moode:~ $ Kernel 4.19.69-v7+, Raspbian 10.0, moOde 6.2.0
____ __
__ _ ___ / __ \___/ /__
/ ' \/ _ \/ /_/ / _ / -_)
/_/_/_/\___/\____/\_,_/\__/
moOde audio player
(C) 2014 Tim Curtis
The programs included with Moode are free software; the
exact distribution terms for each program are described
in the individual files in /usr/share/doc/*/copyright.
Moode comes with absolutely no warranties expressed or
implied, or any other guarantees.
Last login: Fri Oct 11 20:00:26 2019 from 192.168.34.11
pi@moode:~ $ moodeutl -t
737 worker: MPD output 5 ALSA polarity inversion (off)
20191011 200737 worker: MPD output 6 ALSA bluetooth (off)
20191011 200737 worker: MPD output 7 HTTP stream (off)
20191011 200737 worker: MPD crossfade (off)
20191011 200737 worker: Audio source (Local)
20191011 200737 worker: Output device (Local)
20191011 200737 worker: USB auto-mounter (udisks-glue)
20191011 200737 worker: - Music sources
20191011 200737 worker: USB sources (none attached)
20191011 200738 worker: NAS and UPnP sources (mountall initiated)
20191011 200738 worker: - Miscellaneous
20191011 200738 worker: Saved MPD vol level (0)
20191011 200738 worker: Preamp volume level (0)
20191011 200739 worker: MPD volume level (0) restored
20191011 200739 worker: ALSA volume level (None)
20191011 200739 worker: Auto-play (Off)
20191011 200739 worker: Maintenance interval (6 hrs)
20191011 200739 worker: Screen saver activation (Never)
20191011 200739 worker: Session permissions (OK)
20191011 200739 worker: Watchdog started
20191011 200739 worker: Ready
20191011 200850 worker: Job installupd
20191011 200850 updater: Downloading update package r620
20191011 200859 updater: Start 2019-09-12 update for moOde 6.2.0
20191011 200859 updater: ** Version check
20191011 200859 updater: ** Step 1-3: SQL updates
20191011 200859 updater: ** Step 2-3: Code and Config updates
20191011 200902 updater: ** Step 3-3: Syncing changes to disk
20191011 200907 updater: Update installed, REBOOT required
20191011 201059 worker: Job reboot
Kernel 4.19.69-v7+, Raspbian 10.0, moOde 6.2.1
____ __
__ _ ___ / __ \___/ /__
/ ' \/ _ \/ /_/ / _ / -_)
/_/_/_/\___/\____/\_,_/\__/
moOde audio player
(C) 2014 Tim Curtis
The programs included with Moode are free software; the
exact distribution terms for each program are described
in the individual files in /usr/share/doc/*/copyright.
Moode comes with absolutely no warranties expressed or
implied, or any other guarantees.
Last login: Fri Oct 11 20:07:43 2019 from 192.168.34.11
pi@moode:~ $ moodeutl -t
bluetooth (off)
20191011 201130 worker: MPD output 7 HTTP stream (off)
20191011 201130 worker: MPD crossfade (off)
20191011 201130 worker: Audio source (Local)
20191011 201130 worker: Output device (Local)
20191011 201130 worker: USB auto-mounter (udisks-glue)
20191011 201130 worker: - Music sources
20191011 201130 worker: USB sources (none attached)
20191011 201131 worker: NAS and UPnP sources (mountall initiated)
20191011 201131 worker: - Miscellaneous
20191011 201131 worker: Saved MPD vol level (0)
20191011 201131 worker: Preamp volume level (0)
20191011 201131 worker: MPD volume level (0) restored
20191011 201131 worker: ALSA volume level (None)
20191011 201131 worker: Auto-play (Off)
20191011 201131 worker: Maintenance interval (6 hrs)
20191011 201131 worker: Screen saver activation (Never)
20191011 201131 worker: Session permissions (OK)
20191011 201131 worker: Watchdog started
20191011 201131 worker: Ready
20191011 201257 worker: Job installupd
20191011 201258 updater: Downloading update package r621
20191011 201306 updater: Start 2019-10-02 update for moOde 6.2.1
20191011 201306 updater: ** Version check
20191011 201306 updater: ** Step 1-9: Update SQL tables
20191011 201307 updater: ** Step 2-9: Install Raspbian packages
20191011 201307 updater: ** Pkg 1-3: update and upgrade
20191011 202458 updater: ** Pkg 2-3: libgles2
20191011 202509 updater: ** Pkg 3-3: updated MPD dev libs
20191011 202524 updater: ** Step 3-9: Update binaries
20191011 202524 updater: ** Bin 1-6: rotenc_c
20191011 202524 updater: ** Bin 2-6: moodeutl
20191011 202524 updater: ** Bin 3-6: alsa-capabilities
20191011 202524 updater: ** Bin 4-6: install-wifi
20191011 202524 updater: ** Bin 5-6: MPD 0.20.23
20191011 202524 updater: ** Bin 6-6: MPD 0.21.15
20191011 202524 updater: ** Step 4-9: Fix radio station pls file layout
20191011 202530 updater: ** Step 5-9: Update moOde sources and configs
20191011 202538 updater: ** Step 6-9: Install Linux kernel 4.19.75 build #1270
20191011 202741 updater: ** Step 8-9: Install Edimax EW-7811Un fix
20191011 202741 updater: ** Step 7-9: Install drivers for Allo USBridge Signature
20191011 202742 updater: ** Step 9-9: Sync changes to disk
20191011 202742 updater: Update installed, REBOOT required
20191011 202858 worker: Job reboot
Kernel 4.19.75-v7+, Raspbian 10.1, moOde 6.3.0
____ __
__ _ ___ / __ \___/ /__
/ ' \/ _ \/ /_/ / _ / -_)
/_/_/_/\___/\____/\_,_/\__/
moOde audio player
(C) 2014 Tim Curtis
The programs included with Moode are free software; the
exact distribution terms for each program are described
in the individual files in /usr/share/doc/*/copyright.
Moode comes with absolutely no warranties expressed or
implied, or any other guarantees.
Last login: Fri Oct 11 20:25:17 2019 from 192.168.34.16
pi@moode:~ $ moodeutl -t
1 worker: MPD output 5 ALSA polarity inversion (off)
20191011 202931 worker: MPD output 6 ALSA bluetooth (off)
20191011 202931 worker: MPD output 7 HTTP stream (off)
20191011 202931 worker: MPD crossfade (off)
20191011 202931 worker: Audio source (Local)
20191011 202931 worker: Output device (Local)
20191011 202931 worker: USB auto-mounter (udisks-glue)
20191011 202931 worker: -- Music sources
20191011 202931 worker: USB sources (none attached)
20191011 202932 worker: NAS and UPnP sources (mountall initiated)
20191011 202932 worker: -- Miscellaneous
20191011 202932 worker: Saved MPD vol level (0)
20191011 202932 worker: Preamp volume level (0)
20191011 202932 worker: MPD volume level (0) restored
20191011 202932 worker: ALSA volume level (None)
20191011 202932 worker: Auto-play (Off)
20191011 202932 worker: Maintenance interval (6 hrs)
20191011 202932 worker: Screen saver activation (Never)
20191011 202932 worker: Session permissions (OK)
20191011 202932 worker: Watchdog started
20191011 202932 worker: Ready
20191011 203050 worker: Job reboot
Kernel 4.19.75-v7+, Raspbian 10.1, moOde 6.3.0
____ __
__ _ ___ / __ \___/ /__
/ ' \/ _ \/ /_/ / _ / -_)
/_/_/_/\___/\____/\_,_/\__/
moOde audio player
(C) 2014 Tim Curtis
The programs included with Moode are free software; the
exact distribution terms for each program are described
in the individual files in /usr/share/doc/*/copyright.
Moode comes with absolutely no warranties expressed or
implied, or any other guarantees.
Last login: Fri Oct 11 20:29:29 2019 from 192.168.34.11
pi@moode:~ $ moodeutl -t
2 worker: MPD output 5 ALSA polarity inversion (off)
20191011 203122 worker: MPD output 6 ALSA bluetooth (off)
20191011 203122 worker: MPD output 7 HTTP stream (off)
20191011 203122 worker: MPD crossfade (off)
20191011 203122 worker: Audio source (Local)
20191011 203122 worker: Output device (Local)
20191011 203122 worker: USB auto-mounter (udisks-glue)
20191011 203122 worker: -- Music sources
20191011 203122 worker: USB sources (none attached)
20191011 203123 worker: NAS and UPnP sources (mountall initiated)
20191011 203123 worker: -- Miscellaneous
20191011 203123 worker: Saved MPD vol level (0)
20191011 203123 worker: Preamp volume level (0)
20191011 203123 worker: MPD volume level (0) restored
20191011 203123 worker: ALSA volume level (None)
20191011 203123 worker: Auto-play (Off)
20191011 203123 worker: Maintenance interval (6 hrs)
20191011 203123 worker: Screen saver activation (Never)
20191011 203124 worker: Session permissions (OK)
20191011 203124 worker: Watchdog started
20191011 203124 worker: Ready