One of the most common problems seen in Linux distros is the ‘Failed to download repository information’ error when running the software update. Unfortunately, elementary OS also can throw this error over a period of time when third-party software are installed. Actually, the problem is not specifically due to the operating system itself, but the way the updates are delivered from several sources. This is open source world, so there is no single source of updates. Additionally, as you keep installing updates from third-party sources, they add their own repository URLs to the ‘software update’ app of your Linux distro, which may get outdated in future leading to errors, and in this particular case I will shown you how to fix it on elementary OS freya.
Launch ‘Terminal’ and type the following commands one-at-a-time.
sudo apt-get clean sudo apt-get update sudo apt-get upgrade
You should see plenty of updates going on and after it ends, check the process thoroughly, you will find the culprit repository source(S) that was not found and that’s causing the error. Note down the errors or may be just keep the terminal minimized. In this example, we have error:
Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release Unable to find expected entry 'main/binary-i386/Packages' in Release file (Wrong sources.list entry or malformed file)
Go to ‘Applications’ and launch ‘Software Update’.
Click ‘Settings’ after it finishes checking for update.
Go to ‘Other software’ tab. This is where elementary OS stores the software update sources. Go through the repository sources and uncheck the source that was not found in the command terminal. You must enter root password.
Try updating again, it should be a success!