Oh the fun of general and non-specific error messages. The package management system is usually quite well behaved, but when it fails, you can get a series of errors each bewilderingly unhelpful. For instance, Ubuntu Software Center may give you an error telling you that you have no Internet connection and refuse to download any software – even when you’re happily browsing the Internet and downloading gigabytes of files in a different application.
So, what causes this seemingly nonsensical error, and how can you recover? Fortunately, the fix is quite easy.
Many of the ways to recover, advise running
sudo apt-get update
But this may return a long list of errors including one like the following:
BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key
It seems like we’re getting nowhere fast. Although it looks like the Software Center and apt-get errors are unrelated, they are linked to the same problem, which is that the apt list files have become corrupted.
To re-generate them, and fix the problem, try opening a terminal window and running the following:
sudo apt-get clean
sudo rm -r /var/lib/apt/lists
sudo mkdir -p /var/lib/apt/lists/partial
sudo apt-get clean
sudo apt-get update
This deletes the old and corrupted lists files, recreates the directory structure, and then the apt-get commands regenerate the lists.
After running these, apt-get and the Software Center should work again.