Right now I'm upgrading a fairly clean install of 16.04 to 18.04 and it seems to be stuck.

I mean, after some time into the upgrade it went on screen lock and I typed my username and password and it seems to be stuck saying: 'unlocking...'

No idea if this is due to the update still running hogging system resourcing or something else is going on.

I can switch with CtrlAlt+Fkeys but that just gives me black screens and impossible to tell if the upgrade is still running/finished of something terrible happened...

Any idea's? (cant log in with ssh because I haven't installed ssh server on this laptop)

  • now also using alt ctrl + F keys is unresponsive.
    – geegee
    Apr 30 '18 at 10:00
  • Have you tried switching to a terminal (ctrl+alt+f4 or your favorite fn key) and logging in there, looking at what's happening (top, iotop etc)
    – guiverc
    Apr 30 '18 at 10:07
  • @guiverc as mentioned before, they give me a black screen instead of a login.
    – geegee
    Apr 30 '18 at 10:08
  • sorry I didn't know what CTRL+ALT+F did or meant (actually tried the combination on my 18.04 and it did nothing) never realizing you meant Fn keys.
    – guiverc
    Apr 30 '18 at 10:09
  • @guiverc i mean the F-keys (F1 - F12)
    – geegee
    Apr 30 '18 at 10:11

I stumbled into the same issue: Upgrade from 16.04 to 18.04 (on Kubuntu). Screen automatically locked because I didn't use the PC. Entered password, screen is stuck. Switching to the text console - all screens dark. Switching back, mouse courser appears and is responsive, but everything else black.

I then realized:

  1. switching to text console with Ctrl+Alt+F1, the text console was not empty but just very dark. So I increased screen brightness on the laptop with the function keys.

  2. using top I saw that the upgrade probably still running (heavy load on dpkg).

  3. With sudo loginctl unlock-sessions I could unlock the screen savers. I learned this from this answer (full quote for convenience, I used the ):

sudo loginctl unlock-sessions if your system is using systemd. Note that the above will unlock ALL sessions no matter which user is running the screen saver.

If you only want to unlock your own session, just run loginctl unlock-session (no root required because it's your own session).

After that, I changed with Ctrl+Alt+F7 back to KDE and found myself back to the still running session and upgrade process.

  • 6
    I'd give you a thousand upvotes if I could. I absentmindedly locked my screen during my upgrade as I needed to walk away from the computer (at work). Was able to ssh to the machine from another and issue the unlock-sessions command. Thanks!!!
    – Dashdrum
    Aug 16 '18 at 13:25
  • 1
    If there is no effect, make sure to add session id to the command sudo loginctl unlock-sessions $SESSION_ID. You can get the list of session ids by running loginctl.
    – Zheng Qu
    Mar 4 '20 at 12:57

I am also still having this issue, but I found a workaround - Ctrl+Alt+F1 brings me to the normal login screen where I can enter my password and unlock the desktop. This method keeps the original session, so your browser, terminal and other apps are where you left them.

  • I installed 18.04 on my laptop on the 4th (2 days ago) and this started happening to me yesterday. I'd already discovered that I can do the same thing (i.e.: pop over to the "switch user" screen) however, that is a bad solution since it doesn't really fix the problem. It does work though! So, yeah, thanks for contributing a workaround. I'm going keep looking for a fix and publish it here as soon as I find it. Jul 6 '18 at 14:29

As mentioned in the comments, this problem can happen if your lockscreen is on a timeout. So before upgrading make sure you unset a timeout for lockscreen.

To fix a stuck upgrade: Powerdown the pc/laptop and reboot.

Most likely you will find yourself in a partially upgraded system.

In case if you see black screen on booting up, press Ctrl+Alt+F1 keys combination and it will take you to login prompt from where you can run below commands.

You can fix it with:

sudo dpkg --configure --pending
sudo dpkg --configure -a
sudo apt -f install
sudo apt update
sudo apt upgrade
  • 1
    I think the last two commands should be sudo apt-get update and sudo apt-get upgrade Regardless, this had no effect for me.
    – mtutty
    May 31 '18 at 11:17

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