Precise known bugs with workarounds

[CharlesA]

Please post the bugs you have run into and how you worked around them here.

Do not post your problems, please raise a support thread.

Keep in mind, that Linux is infinitely customizable, you do not have to stick with Unity as a desktop environment if you do not want to.

[haqking]

I have posted a workaround thread to the default dnsmasq being hardcoded into networkmanager in 12.04 which leaves users potentially vulnerable to MITM attacks and DNS poisoning especially on open networks where rogue DNS servers could appear.

Thread/workaround here http://ubuntuforums.org/showthread.php?t=1968061

It is not needed as a default configuration, it should be provided as a feature if needed.

Though it appears no caching is happening by default, however instructions above are there if needed.

Peace

[mendhak]

Sometimes LightDM (the login screen) won't let you log in. This might happen if you have set a non-default wallpaper. The login screen will simply say "logging in" and get stuck there. To get around it,

1. Ctrl Alt F1, login
2. Run these commands:
   
   

       sudo apt-get install gdm
       sudo dpkg-reconfigure gdm

3. That installs GDM, and you will need to set it as default in the second command.
4. Reboot
5. Login, set a standard wallpaper (right click desktop)
6. Run this command to set lightdm back
   

   sudo dpkg-reconfigure lightdm

7. Reboot

If that doesn't work and you still get stuck, do a Ctrl+Alt+F1 at the login screen and have a look at the following log files to see what's happening.

sudo less /var/log/lightdm/x-0-greeter.log
sudo less /var/log/lightdm/lightdm.log

[Zukaro]

Default Ubuntu wallpapers will also become the login screen wallpaper (if used as your desktop wallpaper). This is a feature, however, it doesn't work with custom wallpapers (which is a bug). If you're using your own wallpaper it wont appear on the login screen; the way to fix this is to copy it into /usr/share/backgrounds and then set the permissions to read only (set "group" and "other" permissions to read only).

You wont be able to drag the file to the folder as the folder is owned by root, so type "sudo mv /home/username/Pictures/wallpaper.jpg /usr/share/backgrounds" (make sure there's a space between locations); then go to the directory, find the file, right click, go into permissions and change group and other to read only (you're still the owner of the file, which is why you don't need to change permissions through the terminal).

Then to use the wallpaper just select it as your desktop wallpaper and it will also become your login screen wallpaper.

If you want your login screen wallpaper different from your desktop wallpaper download Ubuntu Tweak Tool and follow all the same steps above with the image you want to use instead; then just choose that image in Ubuntu Tweak Tool.




I found out about this bug and the fact the permissions were the issue here:
https://bugs.launchpad.net/ubuntu-tweak/+bug/888186

[Yathi]

I believe adobe flashed has been renamed in Precise Pangolin. So you need to install:

sudo apt-get install adobe-flashplugin

instead of the usual

sudo apt-get install flashplugin-nonfree

[philinux]

If you have ambiance as your theme and you right click the desktop, for example, you'll see a light menu rather than dark like Oneiric.

The discussion surrounding this "design decision" is here.

Bug Report 925895

The fix if you want it is here.

Theme fix for Precise

[Jamie_Edwards]

Default Ubuntu wallpapers will also become the login screen wallpaper (if used as your desktop wallpaper). This is a feature, however, it doesn't work with custom wallpapers (which is a bug). If you're using your own wallpaper it wont appear on the login screen; the way to fix this is to copy it into /usr/share/backgrounds and then set the permissions to read only (set "group" and "other" permissions to read only).

You wont be able to drag the file to the folder as the folder is owned by root, so type "sudo mv /home/username/Pictures/wallpaper.jpg /usr/share/backgrounds" (make sure there's a space between locations); then go to the directory, find the file, right click, go into permissions and change group and other to read only (you're still the owner of the file, which is why you don't need to change permissions through the terminal).

Then to use the wallpaper just select it as your desktop wallpaper and it will also become your login screen wallpaper.

If you want your login screen wallpaper different from your desktop wallpaper download Ubuntu Tweak Tool and follow all the same steps above with the image you want to use instead; then just choose that image in Ubuntu Tweak Tool.




I found out about this bug and the fact the permissions were the issue here:
https://bugs.launchpad.net/ubuntu-tweak/+bug/888186

I don't know if this has already been mentioned but for those who don't like working in the terminal and would rather have a gui, I found another way to copy and paste non-default wallpapers into "usr/share/backgrounds"

NOTE: The following done using Nautilus, it might work with other File Managers but I don't know.

I pressed ALT + F2

This then opens a "Enter command" prompt.
Enter the following:

gksu nautilus

Another prompt will open asking for your password so enter it.

A new window will appear saying "Home" this is nautilus but with root privileges.

Here I like to middle click "File System" so that two tabs open in the window.

In the first tab navigate to your "Home" folder by clicking

File System/usr/[usr_name]/then_location_where_wallpapers_are_saved_to

Obviously clicking on the relevant folders to you.

right click on intended wallpaper and click "copy".

in the second tab navigate to

File System/usr/share/backgrounds

then right click and press "paste".

The wallpaper will then show up on the login screen.

[Cavsfan]

gksu nautilus

One thing: I was told gksu nautilus is no longer supported.
The alternative way is to enter sudo -s, enter your password and then enter nautilus.
You get the same results.
See the 2nd comment here and the last comment here.

[CharlesA]

Thread/workaround here http://ubuntuforums.org/showthread.php?t=1968061

Just so we have the workaround in this thread:

Run this from a terminal:

sudo nano /etc/NetworkManager/NetworkManager.conf

Change the line that says:

dns=dnsmasq

To:

#dns=dnsmasq

Restart Network Manager:

sudo service network-manager restart

Verify /etc/resolv.conf does not say: nameserver 127.0.0.1

cat /etc/resolv.conf

[tolubalogun]

To solve the audio problem, install pavucontrol and go to config menu choosing audio duplex