Mint Cinnamon shows login screen but not desktop

Question

Yesterday I updated my computer using apt and walked away to let it run. I ended up being away from it for a few hours. When I got back I saw that it was done, so I closed the terminal and shut the system down. When I turned it back on later, it got to the login screen but never showed the desktop. Only a black screen with a cursor. I switched to tty1 and that was working normally except apt would not update and I couldn't connect to wifi. I tried googling for solutions and ran journalctl -xe which showed both the network manager and lightdm trying to start and failing.

Here is a list of the packages apt upgraded before this issue started

fdisk:amd64 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
libpackagekit-glib2-18:amd64 (1.1.9-1ubuntu2.18.04.5, 1.1.9-1ubuntu2.18.04.6)
uuid-runtime:amd64 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
libfdisk1:amd64 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
gnupg-utils:amd64 (2.2.4-1ubuntu1.2, 2.2.4-1ubuntu1.3)
python-samba:amd64 (2:4.7.6+dfsg~ubuntu-0ubuntu2.18, 2:4.7.6+dfsg~ubuntu-0ubuntu2.19)
linux-libc-dev:amd64 (4.15.0-117.118, 4.15.0-118.119)
gpg-wks-client:amd64 (2.2.4-1ubuntu1.2, 2.2.4-1ubuntu1.3)
geogebra-classic:amd64 (6.0.604.0-202009091124, 6.0.606.0-202009222237)
gnupg-l10n:amd64 (2.2.4-1ubuntu1.2, 2.2.4-1ubuntu1.3)
libproxy1v5:amd64 (0.4.15-1, 0.4.15-1ubuntu0.1)
libproxy1v5:i386 (0.4.15-1, 0.4.15-1ubuntu0.1)
finalrd:amd64 (3~ubuntu18.04.0, 6~ubuntu18.04.1)
libwbclient0:amd64 (2:4.7.6+dfsg~ubuntu-0ubuntu2.18, 2:4.7.6+dfsg~ubuntu-0ubuntu2.19)
libmount1:amd64 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
libmount1:i386 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
samba:amd64 (2:4.7.6+dfsg~ubuntu-0ubuntu2.18, 2:4.7.6+dfsg~ubuntu-0ubuntu2.19)
libproxy1-plugin-gsettings:amd64 (0.4.15-1, 0.4.15-1ubuntu0.1)
samba-dsdb-modules:amd64 (2:4.7.6+dfsg~ubuntu-0ubuntu2.18, 2:4.7.6+dfsg~ubuntu-0ubuntu2.19)
python3-aptdaemon.gtk3widgets:amd64 (1.1.1+bzr982-0ubuntu19.3, 1.1.1+bzr982-0ubuntu19.4)
gpg-wks-server:amd64 (2.2.4-1ubuntu1.2, 2.2.4-1ubuntu1.3)
util-linux:amd64 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
gpg:amd64 (2.2.4-1ubuntu1.2, 2.2.4-1ubuntu1.3)
cifs-utils:amd64 (2:6.8-1ubuntu1, 2:6.8-1ubuntu1.1)
dirmngr:amd64 (2.2.4-1ubuntu1.2, 2.2.4-1ubuntu1.3)
mount:amd64 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
samba-libs:amd64 (2:4.7.6+dfsg~ubuntu-0ubuntu2.18, 2:4.7.6+dfsg~ubuntu-0ubuntu2.19)
libblkid1:amd64 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
libblkid1:i386 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
busybox-static:amd64 (1:1.27.2-2ubuntu3.2, 1:1.27.2-2ubuntu3.3)
libproxy-tools:amd64 (0.4.15-1, 0.4.15-1ubuntu0.1)
samba-common:amd64 (2:4.7.6+dfsg~ubuntu-0ubuntu2.18, 2:4.7.6+dfsg~ubuntu-0ubuntu2.19)
firefox-locale-en:amd64 (80.0.1+linuxmint1+tricia, 81.0+linuxmint1+tricia)
libuuid1:amd64 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
libuuid1:i386 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
mintdrivers:amd64 (1.4.1, 1.4.5)
gpgv:amd64 (2.2.4-1ubuntu1.2, 2.2.4-1ubuntu1.3)
libproxy1-plugin-networkmanager:amd64 (0.4.15-1, 0.4.15-1ubuntu0.1)
libsmartcols1:amd64 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
rfkill:amd64 (2.31.1-0.4ubuntu3.6, 2.31.1-0.4ubuntu3.7)
python-aptdaemon:amd64 (1.1.1+bzr982-0ubuntu19.3, 1.1.1+bzr982-0ubuntu19.4)
libsmbclient:amd64 (2:4.7.6+dfsg~ubuntu-0ubuntu2.18, 2:4.7.6+dfsg~ubuntu-0ubuntu2.19)
smbclient:amd64 (2:4.7.6+dfsg~ubuntu-0ubuntu2.18, 2:4.7.6+dfsg~ubuntu-0ubuntu2.19)
samba-common-bin:amd64 (2:4.7.6+dfsg~ubuntu-0ubuntu2.18, 2:4.7.6+dfsg~ubuntu-0ubuntu2.19)
aptdaemon-data:amd64 (1.1.1+bzr982-0ubuntu19.3, 1.1.1+bzr982-0ubuntu19.4)
bsdutils:amd64 (1:2.31.1-0.4ubuntu3.6, 1:2.31.1-0.4ubuntu3.7)
libssl1.0-dev:amd64 (1.0.2n-1ubuntu5.3, 1.0.2n-1ubuntu5.4)
gnupg2:amd64 (2.2.4-1ubuntu1.2, 2.2.4-1ubuntu1.3)
code:amd64 (1.49.0-1599744551, 1.49.2-1600965325)
python3-aptdaemon:amd64 (1.1.1+bzr982-0ubuntu19.3, 1.1.1+bzr982-0ubuntu19.4)
gir1.2-packagekitglib-1.0:amd64 (1.1.9-1ubuntu2.18.04.5, 1.1.9-1ubuntu2.18.04.6)
firefox:amd64 (80.0.1+linuxmint1+tricia, 81.0+linuxmint1+tricia)
aptdaemon:amd64 (1.1.1+bzr982-0ubuntu19.3, 1.1.1+bzr982-0ubuntu19.4)
gnupg:amd64 (2.2.4-1ubuntu1.2, 2.2.4-1ubuntu1.3)
python-aptdaemon.gtk3widgets:amd64 (1.1.1+bzr982-0ubuntu19.3, 1.1.1+bzr982-0ubuntu19.4)
gpg-agent:amd64 (2.2.4-1ubuntu1.2, 2.2.4-1ubuntu1.3)
gpgconf:amd64 (2.2.4-1ubuntu1.2, 2.2.4-1ubuntu1.3)
libssl1.0.0:i386 (1.0.2n-1ubuntu5.3, 1.0.2n-1ubuntu5.4)
libssl1.0.0:amd64 (1.0.2n-1ubuntu5.3, 1.0.2n-1ubuntu5.4)
base-files:amd64 (19.0.1, 19.0.2)
gpgsm:amd64 (2.2.4-1ubuntu1.2, 2.2.4-1ubuntu1.3)
busybox-initramfs:amd64 (1:1.27.2-2ubuntu3.2, 1:1.27.2-2ubuntu3.3)

and here is the output of journalctl -x --since='2020-09-30' (pastebin has an upload limit, so I had to trim the log down. I think I got the useful bits. A lot was pages of lightdm saying it couldn't open files.)

Answer 1

If you are running Linux Mint 19 Tara, you are likely affected by the issue announced on The Linux Mint Blog and described in depth on the forums.

Summarizing the relevant forum post:

The issue concerns the base-file 19.0.2 update. The package content is empty and updating it results in creating the /var/run directory, which should be a symbolic link towards /run, preventing many system services from running correctly.

The solution:

1. boot in recovery mode:

   • Boot your computer
   • Press Shift while booting to force the boot menu to show up
   • Select Advanced options for Linux Mint 19
   • Select the "recovery mode" boot option
   • When the Recovery Menu appears, select "root - Drop to root shell prompt"
   • Press Enter

2. You will then be able to type commands. Run the following ones:

   mount -o rw,remount /
   rm -rf /var/run
   ln -s /run /var/run
   

3. Reboot. Your computer should now boot normally and let you log in.

4. To completely fix the issue, open a terminal and type:

   wget linuxmint.com/tmp/base-files_19.0.1_all.deb
   sudo dpkg -i base-files_19.0.1_all.deb