Install Updates could not successfully download and install available updates.

[Raymondo]

Hello, noob here, just tried to install updates but no joy, would be very grateful for assistance!

============ Log ===========

Reading package lists...
Building dependency tree...
Reading state information...
Calculating upgrade...
The following package was automatically installed and is no longer required:
  libqmi-glib1
Use 'apt autoremove' to remove it.
The following NEW packages will be installed:
  libqmi-glib5 linux-headers-4.4.0-112 linux-headers-4.4.0-112-generic
  linux-image-4.4.0-112-generic linux-image-extra-4.4.0-112-generic
The following packages will be upgraded:
  adobe-flash-properties-gtk adobe-flashplugin bind9-host binutils
  chromium-browser chromium-browser-l10n chromium-codecs-ffmpeg-extra cpp-5
  curl distro-info-data dnsutils firefox g++-5 gcc-5 gcc-5-base
  gir1.2-gdkpixbuf-2.0 grub-common grub-pc grub-pc-bin grub2-common
  intel-microcode iproute iproute2 libasan2 libatomic1 libbind9-140 libc-bin
  libc-dev-bin libc6 libc6-dev libcairo-gobject2 libcc1-0 libcilkrts5
  libcurl3-gnutls libdns-export162 libdns162 libegl1-mesa libgbm1 libgcc-5-dev
  libgdk-pixbuf2.0-0 libgdk-pixbuf2.0-common libgfortran3 libgl1-mesa-dri
  libgl1-mesa-glx libglapi-mesa libgles1-mesa libgles2-mesa libgomp1
  libisc-export160 libisc160 libisccc140 libisccfg140 libitm1
  libjavascriptcoregtk-4.0-18 liblwres141 libmbim-glib4 libmbim-proxy
  libmm-glib0 libmpx0 libmysqlclient20 libosmesa6 libpam-systemd
  libpoppler-glib8 libpoppler58 libpython2.7 libpython2.7-minimal
  libpython2.7-stdlib libqmi-proxy libquadmath0 libstdc++-5-dev libstdc++6
  libsystemd0 libtasn1-6 libubsan0 libudev1 libwayland-egl1-mesa
  libwebkit2gtk-4.0-37 libwebkit2gtk-4.0-37-gtk2 libxatracker2 linux-firmware
  linux-generic linux-headers-generic linux-image-generic linux-libc-dev
  lite-manual lite-tweaks lite-upgrade-series3 lite-welcome locales
  mesa-vdpau-drivers modemmanager multiarch-support mysql-common
  openssh-client poppler-utils python2.7 python2.7-minimal rsync systemd
  systemd-sysv thunderbird tor-web-browser ubuntu-mono udev
  update-notifier-common
105 upgraded, 5 newly installed, 0 to remove and 0 not upgraded.
Need to get 475 MB of archives.
After this operation, 152 MB of additional disk space will be used.
WARNING: The following packages cannot be authenticated!
  libcairo-gobject2
E: There were unauthenticated packages and -y was used without --allow-unauthenticated

[Raymondo]

RESOLVED

Menu => All => Software & Updates... browse to the "Other Software" tab, uncheck all xenial.

[Bob]

Thanks for posting this Raymondo.  Your instructions told me where to go and what to do.