The first bug-fix release for KDE Plasma 5.12 LTS was released a day ago. And it can be installed in (K)Ubuntu 17.10 via PPA.

Plasma 5.12.1 adds a one week’s worth of new translations and fixes from KDE’s contributors. The bugfixes are typically small but important and include:

• System Settings: Fix crash when searching.
• Fixed mouse settings module crashing on Wayland.
• Show a beautiful disabled icon for updates.

How to Install Plasma 5.12.1 in (K)Ubuntu 17.10:

Kubuntu backports PPA has just built the packages for (K)ubuntu 17.10.

1. Open terminal via Ctrl+Alt+T or by searching for “Terminal” from start menu. When it opens, run command to add the PPA:

sudo add-apt-repository ppa:kubuntu-ppa/backports

Type in your password when it prompts and hit Enter.

2. Then upgrade your system to get the latest Plasma Desktop via either Update Manager or command:

sudo apt update && sudo apt full-upgrade

After the upgrade process has completed, and assuming everything went well, reboot your computer.

For non-Kubuntu user, you may first install the kubuntu-desktop package either from Ubuntu Software or by running below command before doing the upgrade.

sudo apt update && sudo apt install kubuntu-desktop

How to Uninstall:

To undo the changes and restore to the stock version of Plasma Desktop in your main Ubuntu repository, purge the PPA via command:

sudo apt install ppa-purge && sudo ppa-purge ppa:kubuntu-ppa/backports