2) Uninstall and install commands as root, so you end up with the problem after last reboot:
apt install plymouth-theme-kubuntu-text:all=1:18.04ubuntu11 plymouth- theme-ubuntu-text:amd64=0.9.3-1ubuntu7 plymouth-theme-kubuntu- logo:all=1:18.04ubuntu11 plymouth-theme-ubuntu-logo:amd64=0.9.3-1ubuntu7 plymouth-label:amd64 0.9.3-1ubuntu7 plymouth:amd64=0.9.3-1ubuntu7 apt install plymouth-theme-kubuntu-text:all=1:18.04ubuntu11 apt install plymouth-theme-kubuntu-text:all=1:18.04ubuntu11 apt install plymouth-theme-ubuntu-text:amd64=0.9.3-1ubuntu7 apt install plymouth-theme-kubuntu-logo:all=1:18.04ubuntu11 apt install plymouth-theme-ubuntu-logo:amd64=0.9.3-1ubuntu7 apt install plymouth-label:amd64 0.9.3-1ubuntu7 apt install plymouth-label:amd64=0.9.3-1ubuntu7 apt install plymouth:amd64=0.9.3-1ubuntu7 nano -w /etc/default/grub apt install plymouth:amd64=0.9.3-1ubuntu7 apt install plymouth-theme-kubuntu-logo:all=1:18.04ubuntu11 apt --reinstall install plymouth-theme-kubuntu-logo:all=1:18.04ubuntu11 shutdown -r now nano -w /etc/default/grub update-grub update-grub2 update-initramfs -u apt install plymouth-theme-kubuntu-logo:all=1:18.04ubuntu11 plymouth- theme-kubuntu-text:all=1:18.04ubuntu11 plymouth-theme-ubuntu- text:amd64=0.9.3-1ubuntu7 plymouth-theme-kubuntu- text:all=1:18.04ubuntu11 apt uninstall plymouth-theme-kubuntu-logo:all=1:18.04ubuntu11 plymouth- theme-kubuntu-text:all=1:18.04ubuntu11 plymouth-theme-ubuntu- text:amd64=0.9.3-1ubuntu7 plymouth-theme-kubuntu- text:all=1:18.04ubuntu11 apt remove plymouth-theme-kubuntu-logo:all=1:18.04ubuntu11 plymouth- theme-kubuntu-text:all=1:18.04ubuntu11 plymouth-theme-ubuntu- text:amd64=0.9.3-1ubuntu7 plymouth-theme-kubuntu- text:all=1:18.04ubuntu11 apt install plymouth-label:amd64=0.9.3-1ubuntu7 apt install plymouth-theme-kubuntu-logo:all=1:18.04ubuntu11 plymouth-theme-kubuntu-text:all=1:18.04ubuntu11 plymouth-theme-ubuntu-text:amd64=0.9.3-1ubuntu7 plymouth-theme-kubuntu-text:all=1:18.04ubuntu11 shutdown -r now -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1768647 Title: linux 4.15.0-20-generic messes up plymouth and no prompt for luks password Status in linux package in Ubuntu: Confirmed Bug description: With 4.15.0-19-generic everything works perfect. However, with 4.15.0-20-generic, when I power on the computer, the kde plymouth does not show the textbox to enter the root volume crypts luks password. The logo just stays there like in the attachment. If I uninstall plymouth and remove quiet and splash from GRUB_CMDLINE_LINUX_DEFAULT= && update-initramfs -u it boots in text- only mode and then can enter the password perfectly. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1768647/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
