why is there a (-11-System Error) whenever i run sudo apt-get update?

Question

why is there a (-11-System Error) whenever i run sudo apt-get update?

Something wicked happened resolving 'archive.ubuntu.com:http' (-11 - System error)

Answer 1

Close all programs/windows which have to do with installing software e.g. Synaptic, software-centre and terminals.

Now you should delete the locked files:

You can delete the lock file with

sudo rm /var/lib/apt/lists/lock

you may also need to delete the lock file in the cache directory

sudo rm /var/cache/apt/archives/lock 

and now you should open a terminal and run:

 sudo apt-get update --fix-missing