I am running Ubuntu 18.04 and enabled device encryption during installation. Previously, there came up a nice looking screen and asked for the passphrase for decrypting the drive. I tried to uninstall ghostwriter and executed the command sudo apt autoremove, then I rebooted and now the screen does not appear anymore.
Instead I get an empty purple screen, after approx. 5 seconds the screen color changes to black. Then nothing happens anymore. I then can switch via Ctrl+Alt+F2 and then Ctrl+Alt+F1 to the tty. Here I get a message to failed to connect lvmetad, but I am able to enter the passphrase here and unlock my drive to boot.
How can I repair or reinstall the required packages for the standard passphrase request screen?
EDIT: I am not sure if this might be related, but I also removed 'ghostscript' becuase I confused the apps in the terminal. And then I ran the autoremove. Afterwards I installed ghostscript again.
EDIT 2: It seems autoremove removed a lot of stuff. I was able to find out what packages were removed via:
cat /var/log/dpkg.log | grep remove
And it showed me this list: List of removed packages (pastebin)
EDIT3: After reinstalling ubuntu-desktop the screen is now back and everything looks fine...
I still will let this post here in case someone experiences the same or an comparable issue.
The problem was, that I removed a lot of packages without being aware of it. Since I accidentally removed the ghostscript package when I wanted to remove ghostewriter, and then executed
sudo apt autoremove, autoremove removed a lot of packages which are depending on ghostscript.To solve my problems I had to:
cat /var/log/dpkg.log | grep removeAfterwards, everything was back to normal.