Thank you for taking the time to report this issue and helping to make Ubuntu better. Examining the information you have given us, this does not appear to be a bug report so we are closing it and converting it to a question in the support tracker. We understand the difficulties you are facing, but it is better to raise problems you are having in the support tracker at https://answers.launchpad.net/ubuntu if you are uncertain if they are bugs. You can also find a valid help posting your problem in the support forum of your local Ubuntu's community http://loco.ubuntu.com/ or asking at http://askubuntu.com. For help on reporting bugs, see https://help.ubuntu.com/community/ReportingBugs.
simply, try to remove the ppa you added. plus this upgrading from 11.04 to 12.04 is not officially supported, even if possible. ** Changed in: ubuntu Status: New => Invalid ** Converted to question: https://answers.launchpad.net/ubuntu/+question/202432 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1020943 Title: I cannot upgrade Ubuntu 11.04 to 12.04. Update manager crashes and shows me this: W:Failed to fetch http://ppa.launchpad.net/lorenzo- carbonell/atareao/ubuntu/dists/natty/main/source/Sources 404 Not Found , W:Failed to fetch http://ppa.launchpad.net/lorenzo- carbonell/atareao/ubuntu/dists/natty/main/binary-i386/Packages 404 Not Found , E:Some index files failed to download. They have been ignored, or old ones used instead. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1020943/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs