user@user-HP-Pavilion-Laptop-15-cw0xxx:~$ sudo apt-get updateHit:1 http://gb.archive.ubuntu.com/ubuntu xenial InRelease
Hit:2 http://security.ubuntu.com/ubuntu xenial-security InRelease
Hit:3 http://ppa.launchpad.net/chronobserver/betterdiscordctl/ubuntu xenial InRelease
Hit:4 http://gb.archive.ubuntu.com/ubuntu xenial-updates InRelease
Hit:5 http://gb.archive.ubuntu.com/ubuntu xenial-backports InRelease
Hit:6 https://repo.skype.com/deb stable InRelease
Hit:7 http://ppa.launchpad.net/teejee2008/ppa/ubuntu xenial InRelease
Hit:8 http://ppa.launchpad.net/zorinos/patches/ubuntu xenial InRelease
Hit:9 http://ppa.launchpad.net/zorinos/stable/ubuntu xenial InRelease
Get:10 https://packages.zorinos.com/patches xenial InRelease [11.0 kB]
Hit:10 https://packages.zorinos.com/patches xenial InRelease
Get:11 https://packages.zorinos.com/stable xenial InRelease [9,408 B]
Hit:11 https://packages.zorinos.com/stable xenial InRelease
0% [11 InRelease gpgv 243 kB]Splitting up /var/lib/apt/lists/packages.zorinos.coErr:11 https://packages.zorinos.com/stable xenial InReleaseled
  Clearsigned file isn't valid, got 'NODATA' (does the network require authentication?)
Reading package lists... Error!
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://packages.zorinos.com/stable xenial InRelease: Clearsigned file isn't valid, got 'NODATA' (does the network require authentication?)
W: Failed to fetch https://packages.zorinos.com/stable/dists/xenial/InRelease  Clearsigned file isn't valid, got 'NODATA' (does the network require authentication?)
W: Some index files failed to download. They have been ignored, or old ones used instead.
E: Unable to parse package file /var/lib/apt/lists/gb.archive.ubuntu.com_ubuntu_dists_xenial_main_binary-amd64_Packages (1)
E: Unable to parse package file /var/lib/apt/lists/gb.archive.ubuntu.com_ubuntu_dists_xenial_main_binary-i386_Packages (1)
E: Unable to parse package file /var/lib/apt/lists/ppa.launchpad.net_zorinos_patches_ubuntu_dists_xenial_main_binary-amd64_Packages (1)
E: Unable to parse package file /var/lib/apt/lists/ppa.launchpad.net_zorinos_patches_ubuntu_dists_xenial_main_i18n_Translation-en (1)
W: You may want to run apt-get update to correct these problems
E: The package cache file is corrupted