Make a backup of old sources

cd /etc/apt/
cp sources.list sources.list.OLD

and add only this line to the sources.list

deb http://deb.debian.org/debian/ jessie contrib main non-free

If you get an error like this when trying to update

/etc/apt# apt-get update
Ign http://deb.debian.org jessie InRelease
Hit http://deb.debian.org jessie Release.gpg                                                                                
Hit http://deb.debian.org jessie Release                                                                                    
Hit http://ppa.launchpad.net trusty InRelease                                                                               
Get:1 http://deb.debian.org jessie/contrib amd64 Packages [49.8 kB]                                             
Hit http://ppa.launchpad.net trusty/main amd64 Packages                                                         
Get:2 http://deb.debian.org jessie/main amd64 Packages [6818 kB]                                                          
E: The method driver /usr/lib/apt/methods/https could not be found.                                                  
N: Is the package apt-transport-https installed?

and you can't install the apt-transport-https, make a symlink in /usr/lib/apt/methods to force the apt to use http:

cd /usr/lib/apt/methods
ln -s http https

apt update and installation should work now.

• Debian 8

• https://unix.stackexchange.com/questions/338915/how-to-fix-apt-get-install-f-apt-transport-https-error-404-not-found