i was trying to install winusb
typed in the terminal
sudo add-apt-repository ppa:colingille/freshlight && sudo apt-get update
then got that error when tried to update
Err:18 http://ppa.launchpad.net/fossfreedom/packagefixes/ubuntu xenial/main amd64 Packages 404 Not Found
tried this commands
sudo add-apt-repository ppa:fossfreedom/packagefixes
sudo apt-get update
sudo apt-get install banish404
got same error