[HELP} Update Manager - Requires installation of untrusted packages

I'm new to Ubuntu and just tried running a simple "required" update through the Update Manager but got this message:

[ERROR] "Requires installation of untrusted packages:
The action would require the installation of packages from not authenticated sources."

details:

apparmor apport apport-gtk base-files dosfstools firefox firefox-globalmenu firefox-locale-en gir1.2-dbusmenu-glib-0.4 gir1.2-dbusmenu-gtk-0.4 gnome-control-center gnome-control-center-data initramfs-tools initramfs-tools-bin jockey-common jockey-gtk libdbusmenu-glib4 libdbusmenu-gtk3-4 libdbusmenu-gtk4 libgnome-control-center1 libnm-glib-vpn1 libnm-glib4 libnm-util2 libpci3 linux-generic linux-headers-3.2.0-52 linux-headers-3.2.0-52-generic linux-headers-generic linux-image-3.2.0-52-generic linux-image-generic linux-libc-dev lsb-base lsb-release network-manager pciutils python-apport python-problem-report remmina remmina-common remmina-plugin-rdp remmina-plugin-vnc thunderbird thunderbird-globalmenu thunderbird-gnome-support thunderbird-locale-en thunderbird-locale-en-gb thunderbird-locale-en-us whoopsie xul-ext-ubufox

and it only has a "Close" button.
What do I do?
I use Ubuntu on Asus laptop x201e