Had a well-running Kali (kali-rolling, 64) machine, updated it last week.
Tried installing a pentest tool, it hang. I restarted & now have no GUI, plus I'm looping around a problem (s):

From SE:

Run apt-get update:
----appstreamcli 2138 : G-Lib critical **:10:23 g_atomic_ref_count_dec: assertion 'g_atomic_int_get' (arc) 0' failed
----Reading package lists done

Run dpkg --configure -a:
----Errors were encountered while processing: gnome-shell, gnome-shell-extension-prefs, gnome-theme-kali, chrome-gnome-shell, python2.7-dev,gdm3,initramfs-tools
(including a whole list of 'dependency problems-leaving unconfigured' errors before this list)

----also got these errors at some point: the following packages have unmet dependencies: gnome-theme-kali: depends: kali-themes but it is not going to be installed &
libappstream4: depends: liblmdb0(>=0.9.9) but it is not going to be installed

Run apt --fix-broken install:
-----dpkg error processing archive /var/cache/apt/archives/kali-themes_2021.1.3_all.deb (unpack)
new kali-themes package pre-installation script sub-process returned error exit status 2

Pls assist.