Upgrade 11.10 to 12.04 reports critical error that should be logged

[Familie Kelters]

Upgrade 11.10 to 12.04 reports critical error that should be logged to ubuntu developers.
I've tried the upgrade provided by the ubuntu software update. This error was first shown after reboot to this proces. Later I tried installing from cd with same result. The first upgrade eventually did not proceed while mouse and navigation through the installer window did work I waited another 2 hours, no disk access and no fan. Shutting it down was only possible through hardwarebutton.

Here the details from the message
E:The value 'oneiric' is invalid for APT::Default-Release as such a release is not available in the sources

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1014320/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[linuxlovesme (linuxluvsme)]

Please attach the log files contained in "/var/log/dist-upgrade/"