Known Issues
Installation
The desktop image installer cannot unlock existing encrypted (LUKS) volumes. If you need to make use of existing encrypted volumes during partitioning, then use the "Try Ubuntu without installing" boot option to start a live session, open the encrypted volumes (for example, by clicking on their icons in the Unity launcher), enter your password when prompted to unlock them, close them again, and run ubiquity to start the installer. (1066480)
ARM OMAP4 machines will sometimes boot to a black screen during installation. It's likely that the system has booted fine, but you will need to switch to another tty then back to tty7 (Ctrl+Alt+F1 and then Alt+F7) to get graphics. (1065902)
On a mac with an external display can not run in framebuffer mode error occurs on the 2nd reboot onwards. (1066883)
When using installer to upgrade or reinstall an existing installation with encrypted swap, the installer may fail to reuse the partition. A warning will be shown, however the installation can be completed. The installed system will not have swap activated and users are advised to recreate swap on their systems. Please see advice about adding and activating swap at: https://help.ubuntu.com/community/SwapFaq (1172002)
Installs on very small memory systems may fail to start or exit without completing with no error. It is recommended that swap be created before install for such systems. Please see advice about adding and activating swap at: https://help.ubuntu.com/community/SwapFaq (1172161)
In rare circumstances the 'Next' button on the installer 'Install Type' screen is non-functional. This is intermittent and may be resolved by hitting 'Back' and retrying. (1172572)
openvswitch based interfaces are not started in time during boot. (1084028)
Kernel
There are reports of non-functional HDMI audio on various machines, even with proprietary drivers. In some cases analog built-in audio is affected too. Typically the the audio device does not show up in sound settings at all. (1169984)
On some systems, when opening lid, there is a kerneloops with a suspend/resume failure message seen. (1054732)
Networking
In order to improve compatibility with other local nameserver packages, NetworkManager now assigns IP address 127.0.1.1 to the local nameserver process that it controls instead of 127.0.0.1. If the system's /etc/resolv.conf is absent or is a static file instead of the symbolic link to ../run/resolvconf/resolv.conf installed by default then this static file will have to be updated by the administrator in order to continue using the NetworkManager-controlled nameserver.