Update Manager will not run

[Neil Patulny]

I have been using Ubuntu 12.04 since the day of its release and it's never missed a beat. I'm new to Ubuntu and unclear on how best to report this bug (if it is a bug). The error messages attached have indicated that it is a bug and that I should report it, so I am endeavouring to do so.

I think the problem was caused by my attempting to install Chromium Browser using the Ubuntu Software Centre package. The installation started as normal and then stopped with an error message that I had never seen before. In the upper toolbar (alongside the email icon) there is now a red circle with a white horizontal bar in the centre - when I click on that new icon, the following message appears:

"An error occurred, please run Package Manager from the right-click menu or apt-get in a terminal to see what is wrong. The error message was "Error: Opening the cache (E: Encountered a section with no Package: header, E: Problem with MergeList /var/lib/apt/lists/ gb.archive, ubuntu.com_ubuntu_dists_precise_backports_universe_binary-i386_Packages, E: The package lists or status file could not be parsed or opened)' This usually means that your installed packages have unmet dependencies."

I am not able to run synaptic (this program shuts itself down without error message) and I am unclear on exactly what option to use with apt-get.

I have spent a while reading up on bugs and how to report them but haven't been able to use the other means described - "no bug detected".

I used the command "apt-cache policy pkgname" and received a message with the same compnents of the message quoted above.

I then took two screenshots of error messages I received as I was attempting to burrow into the problem and I will try to attach them here. It seems that I can attach only one of these messages, and have done so.

I can no longer use synaptic or the apt-get package manager - this error kills them both, so future updates appear to be impossible.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Reviewing your bug report it seems that you are experiencing bug 346386. This issue happens when you have tried to update your package information when you are a network that didn't return the right files. This issue can be cleaned up by using the following commands in a terminal:

1.) sudo rm /var/lib/apt/lists/*
2.) sudo apt-get update

Thanks and good luck!

[This is an automated message. I apologize if it reached you inappropriately; please reopen the bug task if it was incorrect.]