Blank desktop after upgrading lubuntu to the next version

I recently have experienced the same problem twice when upgrading two computers - once when upgrading Lubuntu 12.10 to 13.10 and again today when upgrading a second computer from 12.10 to 14.04.

In both cases after logging in the desktop opened to a blank wallpaper - no panel and none of my desktop folders etc. Right clicking the desktop brings up a menu with various options not all of which work. In both cases logging out and back into guest session shows the full desktop with panel and folders etc.

How can I fix this?

I found a simple fix for this particular problem on another forum. The fault seems to lie in personal settings for lxsession which are no longer available in the upgraded version.

From the blank desktop open a terminal. (Ctrl+Alt+T)

Type in

lxpanel  

Press enter.

This should restore your panel so you can open your home folder.

Press Ctrl+ H to show hidden folders.

Open the .config/lxsession folder and delete the Lubuntu folder. Logout and back in, the Lubuntu folder will be re-created with default settings and your desktop should be back. This worked in both instances for me.

(Apologies for any formatting errors, still an amateur at this).

Edit: I may have used the incorrect terminology with regards to upgrading. In both instances I installed from disk and selected the option of installing the new OS over the old while keeping settings and home folder.

Please note:

You can't (or are not supported to) upgrade from 12.10 to 13.10, or from 12.10 to 14.04 LTS.

Anything could break, or produce subtle errors you do not notice initially. What you have attempted (assuming you gave accurate details) is definitely NOT recommended.

There is no certainty that your fix (suggested here) addresses all issues.

Ubuntu is ONLY supported when EITHER upgrading to the next release (while the old is still being supported), OR from LTS to next LTS release (again, while the old LTS is still supported).

eg. 13.10 to 14.04 LTS, and 12.04 LTS to 14.04 LTS

Otherwise, you should do a clean install of the NEW release, after first backing up your data (and any applications settings).

If you encounter this when upgrading from Lubuntu 18.04 to 18.10

In my case, the session manager screen would show options for "LXDE", "LXDE-Qt" and "Lubuntu" and all except "LXDE" would result in a blank desktop with just some icon titles (no icons even) and no panel.

It turns out this was because, for some reason, the upgrade did not install the lxqt package, so I could fix it as follows:

1. If your graphical desktop environment does not work at all, go to a virtual terminal and log in: press Ctrl + Alt + F1.

2. Install the package:

   sudo apt install lxqt
   

3. Log out and in again from your graphical desktop environment, or restart your computer.

4. Since the original LXDE desktop environment has been replaced with a Qt-based version in Lubuntu 18.10, we can uninstall the old one to get rid of that legacy "LXDE" option in the session chooser menu of the session manager screen.

   sudo apt remove lxde-core lxde-common