Although Ubuntu 12.04 Precise Pangolin is LTS release, long term supported and stable GNU/Linux version, it has some issues.
We provide the list with the most common Ubuntu 12.04 Precise Pangolin problems and their solutions.
This article is regularly updated, so stay tuned!
Ubuntu 12.04 can't restart
Ubuntu 12.04 can't restart following the standard reboot procedure:
Click system button in upper right corner > Shut down... > Restart button
It ends up in a black screen.
The reason for the problem could be a BIOS issue or the hardware setup of the system
1) Enter the command in the terminal
sudo gedit /etc/default/grub
2) Find GRUB_CMDLINE_LINUX="" and change it to GRUB_CMDLINE_LINUX=”reboot=efi”
3) Save the file and run the command:
If this is not working, try with some other parameter instead of efi (i.e.: reboot=efi). For detailed list of available parameters read this article.
There is no "Show Desktop" option
By default, Ubuntu 12.04 doesn't have enabled options to show desktop except using shortcut keys Ctrl+Super+D (the Super button is the Windows button in the most cases)
Show Desktop in Ubuntu 12.04 via CompizConfig Settings Manager (the first way)
1) Install and run CompizConfig Settings Manager
2) Click on Desktop category on left sidebar > Click on Ubuntu Unity Plugin > Select the Experimental tab
3) Mark option Show "Desktop Icon" in the launcher
The desktop icon will appear in the Unity launcher and you can click on it in order to show desktop.
For more ways to show desktop in Ubuntu 12.04 read this article.
Unity launcher auto hide problem
Many users compain that after enabling Unity Launcher auto hide, it doesn't show when cursor is moved to the left edge of the screen in Ubuntu 12.04.
The trick here is not how hard the mouse cursor is moved to the left screen edge but how far (or fast). Here are the steps that could help you in using the launcher in the way you like:
1) Install CompizConfig Settings Manager (known by its shortname CCSM)
2) After the installation, start CompizConfig Settings Manager
3) Go to Desktop > Ubuntu Unity Plugin > Experimental tab
4) Find the option "Launcher Reveal Pressure"
5) Default value is 20, but you can change it to any lower
Hibernate option missing
Ubuntu 12.04 doesn't have enabled hibernate feature by default, but you can enable it if your hardware supports hibernation.
1) Create file
2) Add the content:
[Re-enable hibernate by default]
3) Save the file, restart the machine and new menu item should appear under the system button in upper right corner
"Ubuntu 12.04 has experienced an internal error" message
Ubuntu 12.04 contains error reporting system named Apport that can send error information to Ubuntu center in case that something goes wrong on your system. There could be many reported issues caused with various reasons displaying the message error:
"Sorry, Ubuntu 12.04 has experienced an internal error"
The only solution to stop displaying error messages is to disable the Apport, the error reporting system:
1) Run the command
sudo gedit /etc/default/apport
2) Change the value of the "enabled" parameter from "1" to "0" and save the changes
Unity Launcher Hiding Behind Other Windows
In some cases, Unity Launcher goes in the background, behind all windows and the Unity Shell, and it's not possible to move it to the frontend, in front all other windows (what is its default and normal behavior). This happens no matter whether you enabled Unity Launcher auto hide option or not. Usualy, GIMP causes this annoying Unity Launcher's behavior.
Sometime, after some further use and without any additional actions, the computer could freeze for a brief moment and Unity Launcher and Dash could continue to work properly. If this doesn't happen here is the way to restart unity launcher without destroying the session and avoiding computer restarting:
1) Start terminal and run the following command:
Screen will flick a few times and after that everything will be back again.
Can't change Ubuntu 12.04 default font
There is no configuration option for changing default font type and size in Ubuntu 12.04
1) Instal gnome tweak tool:
sudo apt-get install gnome-tweak-tool
2) Start gnome tweak tool either by click on Dash Home and entering "advanced settings" or typing command "gnome-tweak-tool" in the terminal
3) GNOME Tweak Tool window will appear
4) Select the Fonts section on the left
5) Choose your preferent default font, document, monospace and window title font as well as font size and hinting and antialiasing types.
Wireless connection doesn't remember password
Wireless connecton continue asking for password in window "Wireless Connection Authentication Required" every time the computer is started.
1) Click on the connection icon on the taskbar
2) Select the last menu item "Edit Connections..." > Click on the Wireless tab
3) Select you connection and click the Edit button
4) Check "Connect automatically" checkbox on new window and click "Wireless Security" tab
5) Select the connection's Security (usually it is "WEP 40/128-bit Key (Hex or ASCII)")
6) Enter your password in the Key field (you can check the "Show key" checkbox if you want to see what password you entered) and click "Save..." button
GEdit is too slow
GEdit text editor is very slow in Ubuntu 12.04 Precise Pangolin
The solution is to disable File Browser plugin in GEdit.
Start GEdit and select Edit > Preferences > Choose Plugins tab > Deselect File Browser Panel plugin
Ubuntu 12.04 with low RAM is very slow
Ubuntu 12.04 Precise Pangolin could become sluggish and slow on a machine with low memory. In this case Ubuntu accesses the hard disk often and it will impact the performance very much.
Change swappines value. The lower the value is, the longer it takes before Ubuntu starts using the swap partition instead phisical memory. More about Linux swappiness read HERE.
1) Run terminal
2) Enter the command to check out current swappines value
3) The result will probably be 60 (default value in Ubuntu for swappiness)
4) Open file /etc/sysctl.conf in a text editor, e.g.
5) Go to the end of the file and enter the following parameter
# Decrease swappiness value
6) Save the file and restart the computer
"Hot Corner" show desktop doesn't work after restart
Our article describes how to show desktop in Ubuntu 12.04 by enabling "hot corner" feature, but in some cases the feature will not take effect after a computer is restarted.
It seems that unityshell plugin is rewritting the expo plugin configuration. Configure the expo plugin to be loaded after unityshell:
1) Start gconf-editor and find /apps/compiz-1/general/screen0/options/active_plugins key
2) Double-click on the key active_plugins will display edit window
3) Place expo under unityshell and click OK to save the changes
Ctrl+Alt+Backspace doesn't work
Ctrl+Alt+Backspace doesn't restart/kill X server and session.
This feature needs to be enabled:
System Settings... > Keyboard Layout > Options... > Key Sequence to kill X Server > Select option Ctrl+Alt+Backspace
Touchpad stop working
Touchpad can randomly stop working sometimes on laptops/netbooks/notebooks.
Disable touchpad and re-enable it again using shortcut Fn + F7.