This page contains links to the best fixes for the most common Ubuntu problems.
If you think problem's link could be improved or could have a better link, please propose the change in this Ubuntu Forums thread for further discussion.
Warning! Please note down any errors and warnings you encounter as many issues are actually similar but not identical. Thus, a solution applied might not have any effect or might even worsen the problem.
Useful tools for recording errors and warning messages include a text editor, the Print Screen command, etc.
Below are a few locations where you can find logs which might aid you in reproducing or pinpointing the errors:
Some of these logs in /var/log can be accessed via System ======>Administration ====> System logs
Any file with a "." in front of it is a hidden file. To view all hidden files, press Ctrl + H. If you wish to view all hidden files permanently and are using Nautilus, go to Edit =====> Preferences ====> View. Under "Default View", check the box "Show hidden and backup files".
You can use Text Editor to view the .xsession-errors.
This is a hidden file and again, you can use Text Editor view .bash_history. .bash_history can be very useful for pinpointing commands responsible for certain error messages.
Problem: I can't get the installer on the Ubuntu Livecd to run.
Solution: This is one of many possible solutions. If you have a laptop, the ACPI might be causing the installer to not run. At the initial boot screen(where one can see options like "Install to the hard disk, Check cd for defects, etc.") press F6 and type the following code into the command prompt and press Enter. The installer should be able to run now.
Problem: The Ubuntu CD freezes in the middle of installation
Solution: The CD image was probably corrupted during download or burn, or you do not have enough RAM (less than 256 MB) to run the Desktop CD. These instructions will help you get an intact (uncorrupted) CD. If you don't have enough RAM, use the Alternate CD
Problem: I can't create or delete or modify a partition using Gnome Parted Editor (GParted) or I have problems creating or deleting or altering my partitions using GParted on the Ubuntu Live CD. or the Ubuntu Live CD keeps auto-mounting my partitions, thus deleting or altering a partition via GParted on Live CD has no effect.
Solution: Download a partitioning dedicated LiveCD such as the GParted Live CD or the Parted Magic LiveCD and boot from it. You should have no problems modifying, deleting, or creating partitions using the LiveCd. GParted Live CD can be found at http://gparted.sourceforge.net/. Parted Magic LiveCd can be found at http://partedmagic.com/.
Question: Ubuntu keeps crashing on me and complains about cupsd errors.
Solution: Go to System ====> Administration ====> Services. From the Services window, disable Cupsd and Bluetooth printing services. This will stop the Cupsd server from being initiated when Ubuntu starts.
Question: I was installing certain updates or softwares when Gnome or Xserver crashed. Now, when an application or window is open, it doesn't have an icon on the taskbar or the close, maximise and minimise buttons in all my application and windows are gone, or have changed position on the menu bar!
Solution: This is one of many possible solutions. Try pasting the following command into the terminal
sudo dpkg --configure -a
There is a possibility that Gnome might have crashed while updating gnome-panel. After the updates or softwares have finished installing, restart X by logging out and back in, or typing sudo /etc/init.d/gdm restart or simply restart the computer. Gnome should be functioning properly now.
Problem: I get the your session lasted less than 10 seconds error when I try to log into Gnome.
Possible solution #1: This can happen if you're out of disk space. Press Control-Alt-F1 to get to a command prompt. Log in. Then type
sudo apt-get clean rm /tmp/*Then, press Control-Alt-F7 and try logging into Gnome again.
Possible solution #2: This can also happen if you've somehow changed ownership of the ~/.ICEauthority file. So you can change it back by pressing Control-Alt-F1, logging in, and typing
sudo chown username:username ~/.ICEauthority
where username is your username. Then press Control-Alt-F7 and try logging into Gnome again.
Problem: I use Xubuntu and my top and/or bottom pannel disappeared or are "messed up".
Solution: If you use Xubuntu and Xfce, this will happen sooner or later, it seems. Try the procedures at Xubuntu - Xfce Panels. This works in most cases.
Problem: How do I deal with Internet Explorer-only websites?
Solution: Apart from not using them? Try Firefox's User Agent Switcher extension (set to "Internet Explorer" user agent), IE NetRender for Firefox, the Web Page Fixer extension or, if that doesn't work, try ILinux
Troubleshooting apt-get or aptitude or Synaptic package manager errors
Problem: I get this error message:
E: Could not get lock /var/lib/apt/lists/lock - open (11 Resource temporarily unavailable)
Solution: If you have Synaptic Package Manager, Adept Package Manager, Update Manager, or Add/Remove open, close it. Otherwise, issue this command
sudo killall dpkg
More details here
Problem: Help! I get I/O and CRC errors when I'm copying or moving certain files/folders.
Solution: This depends on where you are trying to copy the file or folder from. If the source is a dvd or cd-rom, then the disc might be damaged.
If the source is another partition on your computer, then it could be a hard disk issue like bad sectors. To check for hard disk problems, download smartmontools by running sudo apt-get install smartmontools. To run smartmontools, use
sudo smartctl -d ata -a /dev/sda
where sda can be substituted with the device label of your hard disk like hdc, hda, etc. The following article explains more about bad sectors while the site itself contains various articles about hard disk backup, recovery and other issues: Article about bad sectors.