Tor browser not starting after upgrade to 8.0 in Qubes

I have updated Tor Browser to 8.0 and it restarted just fine. However, after shutting down the VM and restarting it, the browser no longer starts. Error:

########################################################### ## torbrowser script bug. ## No panic. Nothing is broken. Just some rare condition ## has been hit. Try again later. There is likely a ## solution for this problem. Please see the Whonix News, ## Whonix User Help Forum and Whonix Documentation. ## https://www.whonix.org/wiki/Tor_Browser ## Please report this bug! ## ## BASH_COMMAND: "$tb_browser_folder/Browser/start-tor-browser" --allow-remote "$@" ## exit_code: 255 ## ## output: /usr/lib/msgcollector/msgcollector ## output_opts: --icon /usr/share/icons/anon-icon-pack/tbupdate.ico --parentpid 5336 --identifier torbrowser --parenttty none --whoami user ## progressbaridx: ## ## Experts only: ## bash -x torbrowser ###########################################################

Output of bash -x torbrowser:

user@host:~$ bash -x torbrowser
+ set -o pipefail
+ set -o errtrace
++ basename /usr/bin/torbrowser
+ SCRIPTNAME=torbrowser
+ IDENTIFIER=torbrowser
+ ICON=/usr/share/icons/anon-icon-pack/tbupdate.ico
+ trap tb_error_handler ERR
+ main_function
+ root_check
++ id -u
+ '[' 1000 '!=' 0 ']'
+ true
+ tb_preparation
+ '[' -n '' ']'
+ tb_home_folder=/home/user/.tb
+ '[' -n '' ']'
+ tb_cache_folder=/home/user/.cache/tb
+ shopt -s nullglob
+ local i
+ for i in '/etc/torbrowser.d/*.conf'
+ bash -n /etc/torbrowser.d/30_default.conf
+ source /etc/torbrowser.d/30_default.conf
+ '[' -n '' ']'
+ tb_browser_folder=/home/user/.tb/tor-browser
+ '[' '' = '' ']'
+ '[' :0 = '' ']'
+ display=:0
+ output=/usr/lib/msgcollector/msgcollector
+ local my_tty
+ local my_tty_exit_code
+ my_tty_exit_code=0
++ tty
+ my_tty=/dev/pts/0
+ '[' '!' 0 = 0 ']'
+ '[' /dev/pts/0 = '' ']'
++ whoami
+ who_ami=user
+ output_opt_1='--icon /usr/share/icons/anon-icon-pack/tbupdate.ico'
+ output_opt_2='--parentpid 5637'
+ output_opt_3='--identifier torbrowser'
+ output_opt_4='--parenttty /dev/pts/0'
+ output_opt_5='--whoami user'
+ output_opts=("$output_opt_1" "$output_opt_2" "$output_opt_3" "$output_opt_4" "$output_opt_5")
+ TITLE='Tor Browser Starter (by Whonix developers)'
+ tb_set_links
+ DOC_LINK=https://www.whonix.org/wiki/Documentation
+ CONTRIBUTE_LINK=https://www.whonix.org/wiki/Contribute
+ DONATE_LINK=https://www.whonix.org/wiki/Donate
+ FORUM_LINK=https://forums.whonix.org
+ MAILINGLIST_LINK=https://www.whonix.org/pipermail/whonix-devel/
+ IMPORTANTBLOG_LINK=https://www.whonix.org/blog/category/important
+ FEATUREBLOG_LINK=https://www.whonix.org/blog/
+ '[' '!' '' = '' ']'
+ '[' -f /usr/share/anon-ws-base-files/workstation ']'
+ local whonix_homepage
+ whonix_homepage=/usr/share/homepage/whonix-welcome-page/whonix.html
+ '[' -f /usr/share/homepage/whonix-welcome-page/whonix.html ']'
+ DEFAULT_LINK=file:///usr/share/homepage/whonix-welcome-page/whonix.html
+ open_link_confirmation_maybe_skip=true
+ parse_cmd_options
+ :
+ case $1 in
+ break
+ local other_args
+ other_args=
+ '[' '' = '' ']'
+ '[' '' = '' ']'
+ LINK=file:///usr/share/homepage/whonix-welcome-page/whonix.html
+ '[' true = true ']'
+ open_link_confirmation_skip=true
+ maybe_install_tor_browser
+ '[' -d /home/user/.tb/tor-browser ']'
+ return 0
+ tb_folder_change_directory
+ local change_directory_exit_code=0
+ cd /home/user/.tb/tor-browser
+ '[' '!' 0 = 0 ']'
+ maybe_use_open_link_confirmation
+ '[' '' = true ']'
+ tool=tb_start_tor_browser
+ '[' -x /usr/lib/open_link_confirmation ']'
+ '[' '!' true = true ']'
+ '[' file:///usr/share/homepage/whonix-welcome-page/whonix.html = '' ']'
+ tb_start_tor_browser file:///usr/share/homepage/whonix-welcome-page/whonix.html
+ '[' -x /home/user/.tb/tor-browser/Browser/start-tor-browser ']'
+ /home/user/.tb/tor-browser/Browser/start-tor-browser --allow-remote file:///usr/share/homepage/whonix-welcome-page/whonix.html
++ tb_error_handler
++ local exit_code=255
++ local 'MSG=###########################################################
## torbrowser script bug.
## No panic. Nothing is broken. Just some rare condition
## has been hit. Try again later. There is likely a
## solution for this problem. Please see the Whonix News,
## Whonix User Help Forum and Whonix Documentation.
## https://www.whonix.org/wiki/Tor_Browser
## Please report this bug!
##
## BASH_COMMAND: "$tb_browser_folder/Browser/start-tor-browser" --allow-remote "$@"
## exit_code: 255
##
## output: /usr/lib/msgcollector/msgcollector
## output_opts: --icon /usr/share/icons/anon-icon-pack/tbupdate.ico --parentpid 5637 --identifier torbrowser --parenttty /dev/pts/0 --whoami user
## progressbaridx: 
##
## Experts only:
## bash -x torbrowser
###########################################################'
++ mkdir --parents /home/user/.cache/tb
++ echo '###########################################################
## torbrowser script bug.
## No panic. Nothing is broken. Just some rare condition
## has been hit. Try again later. There is likely a
## solution for this problem. Please see the Whonix News,
## Whonix User Help Forum and Whonix Documentation.
## https://www.whonix.org/wiki/Tor_Browser
## Please report this bug!
##
## BASH_COMMAND: "$tb_browser_folder/Browser/start-tor-browser" --allow-remote "$@"
## exit_code: 255
##
## output: /usr/lib/msgcollector/msgcollector
## output_opts: --icon /usr/share/icons/anon-icon-pack/tbupdate.ico --parentpid 5637 --identifier torbrowser --parenttty /dev/pts/0 --whoami user
## progressbaridx: 
##
## Experts only:
## bash -x torbrowser
###########################################################'
++ '[' '' = '' ']'
++ true
++ /usr/lib/msgcollector/msgcollector --icon /usr/share/icons/anon-icon-pack/tbupdate.ico --parentpid 5637 --identifier torbrowser --parenttty /dev/pts/0 --whoami user --messagex --typex error --titlex 'Tor Browser Starter (by Whonix developers)' --message '###########################################################
## torbrowser script bug.
## No panic. Nothing is broken. Just some rare condition
## has been hit. Try again later. There is likely a
## solution for this problem. Please see the Whonix News,
## Whonix User Help Forum and Whonix Documentation.
## https://www.whonix.org/wiki/Tor_Browser
## Please report this bug!
##
## BASH_COMMAND: "$tb_browser_folder/Browser/start-tor-browser" --allow-remote "$@"
## exit_code: 255
##
## output: /usr/lib/msgcollector/msgcollector
## output_opts: --icon /usr/share/icons/anon-icon-pack/tbupdate.ico --parentpid 5637 --identifier torbrowser --parenttty /dev/pts/0 --whoami user
## progressbaridx: 
##
## Experts only:
## bash -x torbrowser
###########################################################' --done
++ /usr/lib/msgcollector/msgcollector --icon /usr/share/icons/anon-icon-pack/tbupdate.ico --parentpid 5637 --identifier torbrowser --parenttty /dev/pts/0 --whoami user --messagecli --typecli error --titlecli 'Tor Browser Starter (by Whonix developers)' --message '###########################################################
## torbrowser script bug.
## No panic. Nothing is broken. Just some rare condition
## has been hit. Try again later. There is likely a
## solution for this problem. Please see the Whonix News,
## Whonix User Help Forum and Whonix Documentation.
## https://www.whonix.org/wiki/Tor_Browser
## Please report this bug!
##
## BASH_COMMAND: "$tb_browser_folder/Browser/start-tor-browser" --allow-remote "$@"
## exit_code: 255
##
## output: /usr/lib/msgcollector/msgcollector
## output_opts: --icon /usr/share/icons/anon-icon-pack/tbupdate.ico --parentpid 5637 --identifier torbrowser --parenttty /dev/pts/0 --whoami user
## progressbaridx: 
##
## Experts only:
## bash -x torbrowser
###########################################################' --done
[ERROR] [torbrowser] ###########################################################
## torbrowser script bug.
## No panic. Nothing is broken. Just some rare condition
## has been hit. Try again later. There is likely a
## solution for this problem. Please see the Whonix News,
## Whonix User Help Forum and Whonix Documentation.
## https://www.whonix.org/wiki/Tor_Browser
## Please report this bug!
##
## BASH_COMMAND: "$tb_browser_folder/Browser/start-tor-browser" --allow-remote "$@"
## exit_code: 255
##
## output: /usr/lib/msgcollector/msgcollector
## output_opts: --icon /usr/share/icons/anon-icon-pack/tbupdate.ico --parentpid 5637 --identifier torbrowser --parenttty /dev/pts/0 --whoami user
## progressbaridx: 
##
## Experts only:
## bash -x torbrowser
###########################################################
++ exit 1

I have tried reinstalling the browser (version 8.0) using Tor Browser Downloader, but I get this error:

ERROR: GPG download signature could NOT be verified. 
Tor Browser update failed! Try again later. 
gpg_bash_lib_output_alright_status: 
gpg_bash_lib_output_failure: 
gpg_bash_lib_output_diagnostic_message: 
gpg_bash_lib_internal_gpg_verify_status_fd_file: /home/user/.cache/tb/gpgtmpdir/gpg_bash_lib_internal_gpg_verify_status_fd_file
gpg_bash_lib_internal_gpg_verify_output_file: /home/user/.cache/tb/gpgtmpdir/gpg_bash_lib_internal_gpg_verify_output_file
gpg_bash_lib_output_gpg_import_output:
gpg: key 93298290: public key "Tor Browser Developers (signing key) " imported
gpg: Total number processed: 1
gpg: imported: 1 (RSA: 1)
gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
gpg: depth: 0 valid: 2 signed: 1 trust: 0-, 0q, 0n, 0m, 0f, 2u
gpg: depth: 1 valid: 1 signed: 0 trust: 1-, 0q, 0n, 0m, 0f, 0u
gpg: next trustdb check due at 2020-08-24
gpg_bash_lib_output_gpg_verify_output:
gpg: Signature made Tue 04 Sep 2018 11:08:33 AM UTC using RSA key ID D9FF06E2
gpg: Can't check signature: public key not found
gpg_bash_lib_output_gpg_verify_status_fd_output:

Is there a way to fix this?

which Qubes and Whonix version r u using?

Qubes 4.0, Whonix 13

install whonix 14:

either by: (preferable one)

or by:

A post was split to a new topic: Qubes-Whonix does not boot after upgrade from Qubes-Whonix 13 to Qubes-Whonix 14