Unity problems after installing GNOME desktop (ubuntu-gnome-desktop)

Question

I accidentally installed ubuntu-gnome-desktop (initially with lightdm, and later switched to gdm3) on my heavily customized Ubuntu (Unity) 16.10 environment. Yikes! Now a bunch of stuff in Unity doesn't work as it did before. I need help fixing some unresolved problems. Can you please help?

1. Desktop problems

   • In Unity, I can't set desktop background
   • In Unity, the superkey doesn't bring up dashboard unless another application is in the foreground
   • In Unity, the desktop files and folders are gone
   • In Unity, I can't right-click on the desktop and bring up the contextual menu

2. Font problem

   • In Unity, the default fonts have changed

3. Touchpad problems

   • In Unity, the touchpad-indicator crashes, looking for Synaptics touchpad driver
   • In Unity, the touchpad "tap to single-left-click" no longer works
   • In Unity, the touchpad preferences are missing in System Settings/Mouse & Touchpad panel
   • In Gnome, the touchpad preferences do show up in System Settings

I believe that this is because xserver-xorg-input-libinput got installed, thereby disabling the Synaptics touchpad driver. Can I safely uninstall this, and hopefully re-enable the Synaptics driver, without breaking anything in the Unity desktop, or the Gnome desktop?

4. Login screen problem

   • The main login screen background is black. How do I get any background to show again?

5. Default DE problem

   • The login area always shows "Gnome (Default)" in the list of desktop environments. How do I change the default to "Ubuntu (Default)"?

6. Boot/shutdown screens problem

   • Boot and shutdown screens are Gnome animation/text screens. How do I bring back normal Ubuntu/Unity boot/shutdown screens?

Solution 1

Fixes for my ubuntu-gnome-desktop post-installation problems...

1. Desktop problems: Use the Gnome Tweak Tool, and set "Icons on Desktop" to ON

2. Font problem: Use the Unity Tweak Tool, and set the fonts back to Ubuntu default fonts

3. Touchpad problems: Fix taken from How to invert touchpad scrolling on Ubuntu 16.04

If you use libinput, then add a config file to /etc/X11/xorg.conf.d/ such as 20-touchpad.conf with this content:

Section "InputClass"
    Identifier "libinput touchpad catchall"
        MatchIsTouchpad "on"
        MatchDevicePath "/dev/input/event*"
        Driver "libinput"
        Option "NaturalScrolling" "off"
        Option "MiddleEmulation" "on"
        Option "Tapping" "on"
        Option "DisableWhileTyping" "on"
        Option "PalmDetection" "True"
EndSection

4. Login screen problem: User desktop must be set to display a desktop picture, not a solid color

5. Default DE problem:

In terminal...

gksudo gedit /etc/lightdm/lightdm.conf

add in this text snippet under [SeatDefaults]...

[SeatDefaults]
user-session=ubuntu

don't duplicate [SeatDefaults] if it's already there.

6. Boot/shutdown screens problem: Partially taken from How do I revert the Plymouth theme back to default after purging Kubuntu?

In terminal...

ls -al /etc/alternatives/*plymouth*
sudo update-alternatives --config default.plymouth
sudo update-alternatives --config text.plymouth

Solution 2

The Touchpad problem could be resolved by removing the xserver-xorg-input-libinput package.

sudo apt remove xserver-xorg-input-libinput

I had the same problem and removing package solved it without making any other problems. Note: I have removed Gnome Shell completely before removing this package.

Source: this Ubuntu Forums post

Comments

[Boris Hamanov]

@ElderGeek thanks for your input. I haven't tried to remove ubuntu-gnome-desktop for fear of creating more Unity problems. I figure that now that it's installed, I might as well try it (I was going to install it into a Virtualbox environment to test it) since we're all going to it next year. By pristine 16.10 I meant a long-running, clean, problem-free, installation with a ton of apps and customizations.

[Boris Hamanov]

@ElderGeek I'll go and change "pristine" in my question to something else. No, I meant that we'll all be going to Gnome in 18.04... if plans stick to schedule. That's why I wanted to play with Gnome... but in a VB environment... not my normal Unity machine.

[Organic Marble]

In stock Ubuntu, setting the session background image also sets the login screen background image. Is that no longer working?

[Boris Hamanov]

@OrganicMarble thanks for your input. Let me see if I get this straight... my lock screen is the same as my desktop background, but my login screen is black with the normal username/password login area.

[Organic Marble]

Interesting! I don't know about lock-screen because I use xscreensaver. But on my system, setting the user's background also sets the login background. Sounds like that is not working any more for you.

[Elder Geek]

While all of these issues may have had the same cause, It's far more likely that someone will be experiencing one of them than all of them. IMHO this question is too broad. I recommend splitting this into more specific pieces.

[Boris Hamanov]

@ElderGeek you're probably right. I thought that it might be good to put all of my symptoms, and their partial solutions, under one roof, so that somebody going through the same thing would understand how to solve some of them, and to know what else might go wrong. When I was researching this, there were TONS of questions regarding the same topic, but only 1 or 2 had any hard solutions... hence my questions.

[Elder Geek]

@heynnema my point exactly. Splitting it up would allow for "somebody going through the same thing would understand how to solve some of them" Not surprising the lack of answers on such a broad topic, The surprising thing is the ostensibly TONS of questions on the same topic.

[Boris Hamanov]

@ElderGeek only one problem left to solve!

[Boris Hamanov]

@OrganicMarble only one problem left to solve!

[Boris Hamanov]

@ElderGeek thanks for your offer. Although it's a mouthful, I think that I'd like to keep all of these problems/updates under one roof, a roll up of various gnome issues for the gnome updater to see, without having to look through the tons of other posts looking for the answer(s)... however, if you see a way to add value by separating this into separate questions, and you'd like to copy off select portions (without editing this one) of it and create new questions/answers, please help yourself.

[Boris Hamanov]

@ElderGeek I wouldn't be insulted if you used portions of mine for your Q&A. Cheers, Al

[Boris Hamanov]

@ElderGeek the reason that I do a ls -al /etc/alternatives/*plymouth* first is to show that the are actually 3 values that need to get reset. One update-alternatives command resets only 2 of the values at the same time, and the other update-alternatives command resets the 3rd value. One for the graphics screens, and one for the text screens.

[Elder Geek]

With all due respect the issue you refer to solving is the "boot and shutdown screens are Gnome animation screens" with no mention of text screens and sudo update-initramfs -u isn't required at all to resolve this.

[Elder Geek]

Let us continue this discussion in chat.

[Elder Geek]

FYI: Regarding 6 my testing indicates that sudo update-initrams -u isn't required. Simply choosing the correct option from sudo update-alternatives ... and rebooting is sufficient.

[Boris Hamanov]

@ElderGeek and the boot screen (not the shutdown/reboot screen) is correctly changed to the desired type? It would be interesting to see if the mod date of /boot/initrd.img* changes after the update-alternatives... can you check your mod dates?

[Elder Geek]

If by boot screen you mean ubuntu with the 5 dots, then as opposed to the weird u's on the gnome boot screen, then yes. If you mean something else can you define it for me?

[Boris Hamanov]

@ElderGeek yes, you have it right... the Ubuntu/Unity 5 dots boot screen vs the Gnome interlocked U's boot screen. Assuming that you didn't do the update-initramfs command, do a ls -al /boot/initrd* and see if the most recent one has todays date for a mod date.

[Elder Geek]

Why not try it yourself? Switch back to the gnome boot screen and don't update-initramfs and there;s your proof. When done, simply change it back! :-)

[Boris Hamanov]

I will try it, when I'm a little less gun shy. I've just spent 2 days gluing my system back together, and I'm not going to touch it for a little while. Would you just check your mod date for us, and we'll know... :-)

[Elder Geek]

Let us continue this discussion in chat.

[Boris Hamanov]

This was a part of my original question. Further research is required, as I read one post where the user had removed this package, and it broke their system. In the mean time, I have proposed an elegant solution that works.

[Hamed]

I had the same problem, removed the package and everything is working now.