My OS: Linux Mint 13 KDE 64-bit.
The update manager is set to levels 1, 2, 3 and 4.

The update manager prompted to update 218 packages which was successfully completed. I closed the update manager. Firefox and Thunderbird were working and all appeared to be okay.

However after restarting the computer I was prompted to enter my password although I enabled Auto-Login a long time ago.

Well, I entered my password and then noticed that my customised wallpaper had changed to the Linux Mint Maya default wallpaper which appears to be somewhat oversized.
The desktop has no taskbar anymore, I left/right click the desktop but no responses.
However I am able to press Alt+F2 to open the Application Launcher Menu.

I double-checked the monitor resolution settings in both 'Size & Orientation' and 'NVIDIA settings' which has not changed and still is 1360x768.

According to KInfo Centre the KDE SC Version is now 4.12.2 and I suspect that this particular update/upgrade is the culprit.

I Googled for possible solutions and found this:

Code: Select all

sudo apt-get install ppa-purge
sudo ppa-purge ppa:kubuntu-ppa/backports
sudo apt-get autoremove

But am unsure if this is the correct course of action as I really don't want to foul up any further.

I kindly request an expert guiding hand to remove safely version 4.12.2 and to re-install the previous version of KDE SC 4.8.5 or 4.9 (I forget what my previous version was).

Many thanks in advance.

Please check in your package manager (likely Apper) that all updates successfully installed, and that there are no further updates awaiting installation.
Also, please try to create a new user and see if Plasma Desktop loads appropriately there.

Thanks for responding.

I opened Synaptic Package Manager and clicked the 'Reload' button. All seems okay, I can't identify any broken packages and there seems that no further updates are in waiting.

I then entered 'Apper' in the 'Quick filter' - the Packages 'apper' Latest version 0.7.1-1ubuntu1 and 'apper-dbg' 0.7.1-1ubuntu1 are not installed.

Should both pakages be installed?
(Please note that I am mot a techie )

Apper is simply a more KDE friendly frontend to the package manager - it has the same role as Synaptic. It is not necessary to install it if you are using Synaptic.

Does the desktop appear correctly under a new user?

No. The desktop appeared to be pitch-black and didn't respond to any mouse clicking. Anyway, I did reset the update manager to its default settings and then tried to uninstall/remove KDE via Synaptic Package Manager - removing anything related to KDE 4.12.2. This was a huge mistake! Now I can't access the system (probably removed to many applications etc.). I was hoping that updating in recovery mode (network - dbk) would fix it but it didn't. Luckily I dual boot with another distro (this is where I am writing this post from) and I am able to safe all my data etc. via Dolphin. I am preparing to reinstall; It's easy, fast, less complex and time consuming than trying to fix my original foul-up, and more importantly one doesn't have to be a techie! Unlike other desktop environments I had no idea that KDE so difficult & complicated to remove (or change to another version), it sticks like super-glue to the system - oh well. Next time I won't enable the number 4 in the update manager or might give (the less attractive) Cinnamon desktop a try...
Many thanks for your responses.
Cheers... Kanjana.

Please note that upgrading a desktop environment on a system is not a simple task due to the number of components which comprise a desktop environment. I would recommend sticking to the mainline distribution repositories in your case, which should only offer safe, patch level, updates.

Well, the upgrading actually was painless - it just resulted in an unworkable desktop environment. Downgrading (or restoring to an previous version) seems to be the real problem. In any case, we wouldn't have this exchange of messages if I hadn't enabled #4 in the update manager - mea culpa! (I must stop being so adventurous).
Cheers...