upgrade 14.04 with errors and shows red sign on top

Question

I upgraded to Ubuntu 14.04 but it shows a red symbol on the top and gives error message in function update

E:unknown error:<type exceptions.type error> upgrade manager or any other file is not present

Answer 1

This can damage stuff. Do not run these commands unless you know what you're doing!

Hi Please try these options

sudo rm /var/lib/apt/lists/* -vf 

then

sudo apt-get update

or

sudo apt-get -f install