Ubuntu hangs at boot after upgrade

I've been using Ubunth 20.04 for a few months. Fresh install.

I decided to update to 20.10 and it appeared to go smoothly. However, after I rebooted all I could see was this:

/dev/sda5: clean, 764403/30498816 files, 30197898/121964800 blocks

Not sure what happened, but when I press the power button, it instantly starts shutting down, including showing the graphical splash screen.

At startup, I do see my graphical boot splash. When pressing Ctrl+ ESC, I can see the startup terminal with a few dependency errors...

I'm not entirely sure what to do next... keys do nothing, but Ctrl+Alt+F1 briefly shows the startup terminal, then shows a blank screen with a text cursor. I still can't do anything.

What should I do next?

EDIT 1: I have access to the rescue mode, but I don't have network access. If I could enable networking, I should be able to update some packages.

EDIT 2: I was able to boot to rescue mode with networking and install the package it was complaining about. However, when booting normally, my laptop hangs on this...

EDIT 3: I was able to upgrade to Ubuntu 21.04, which I originally wanted to do anyways. I'm now back at the beginning with the same message I started with, just with different numbers.

Solution 1:

sudo apt-get update
sudo apt-get upgrade -y
sudo apt-get dist-upgrade
sudo do-release-upgrade

Edit: this should solve your network problems

sudo touch /etc/NetworkManager/conf.d/10-globally-managed-devices.conf
sudo systemctl restart NetworkManager

Solution 2:

To enable networking in emergency mode, try to use:

/etc/init.d/network-manager restart

Verify then with ifconfig that your connection is up. There are other commands like ifup or nmcli that you might try if the above doesn't work. See systemd-networkd - No networking in recovery mode