When upgrading to Ubuntu 14.04 from Ubuntu 12.04 I am getting the following error:

W:Failed to fetch http://deb.opera.com/opera-beta/dists/stable/Release Unable to find expected entry 'non-free/source/Sources' in Release file (Wrong sources.list entry or malformed file) , E:Some index files failed to download. They have been ignored, or old ones used instead.

2 Answers 2


You probably had a ppa before for installing Opera? If that is the case then it's likely that that ppa has not yet been updated for 14.04.

You can remove the offending item from your sources list by pressing the Super key and getting up 'Software & Updates', going through to the 'Other Software' tab and unticking the opera entry. (This will get rid of the error).

To actually get Opera back, I would have a look on their site, or use the instructions here:



The accepted answer is actually wrong. As I explain in more details HERE, the real problem is that the path to the official Opera repositories have changed but the Opera DEB installation packages weren't reconfigured to reflect this change.

The change in repo location affects those who already were Opera users. And the lack of reconfiguration of the DEB installation packages affects new Opera users.

In order to fix this issue, all you have to do is to execute these commands at the shell terminal:

  • If you're using Opera stable:

    sudo sed -i -e 's,opera-stable/ stable,opera-stable/opera/ stable,' "/etc/apt/sources.list.d/opera-stable.list" ; sudo apt-get update ; sudo apt-get check
  • If you're using Opera Beta stable:

    sudo sed -i -e 's,opera-beta/ stable,opera-beta/opera/ stable,' "/etc/apt/sources.list.d/opera-beta.list" ; sudo apt-get update ; sudo apt-get check
  • Yesterday I sent an e-mail to the Opera business contact, reporting this issue (the wrong configuration inside the DEB packages). I was expecting the company to fix the packages (by adding the opera directory to the repository path inside of each DEB package), but instead the company decided to fix the directory hierarchy (by removing the opera directory from both repositories). Hence, my solution above won't work anymore. Despite of it, I will keep this answer here for future reference: it may help understand folder hierarchy in repository configuration files. Sep 22, 2016 at 18:31
  • I've just accessed deb.opera.com/opera-stable and deb.opera.com/opera-beta and noticed that the opera folder is gone and the dists folder is now back in its place. Hence, if anyone did what I proposed on my answer above, just run the commands sudo sed -i -e 's,opera-stable/opera/ stable,opera-stable/ stable,' "/etc/apt/sources.list.d/opera-stable.list" ; sudo apt-get update ; sudo apt-get check and sudo sed -i -e 's,opera-beta/opera/ stable,opera-beta/ stable,' "/etc/apt/sources.list.d/opera-beta.list" ; sudo apt-get update ; sudo apt-get check to undo it. Sep 22, 2016 at 18:36

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