/etc/qubes-rpc/policy/qubes.UpdatesProxy
Make sure your sys-net is the correct one.
I use fedora26 default, it prompt update icon, so i try to click "update qubes", but it doesnt popup anything, i tried to connect sys-firewall to it still no function.
Open a dom0 terminal (xterm/uxterm) and type 'journalctl -f'
then open a fedora-26 terminal and type 'sudo yum update'
then tell us what it says on the dom0 journalctl output.
Type 'sudo vi /etc/qubes-rpc/policy/qubes.UpdatesProxy'
Its going to look like this:
$type:TemplateVM $default allow,target=sys-whonix
$tag:whonix-updatevm $default allow,target=sys-whonix
$tag:whonix-updatevm $anyvm deny
## Note that policy parsing stops at the first match,
## so adding anything below "$anyvm $anyvm action" line will have no effect
## Please use a single # to start your custom comments
# Default rule for all TemplateVMs - direct the connection to sys-net
$type:TemplateVM $default allow,target=sys-net
Make sure the last line points to your sys-net.
Go into your sys-net qube settings. (Right click>settings>Services)
Go to the last tab, Services. Type "qubes-updates-proxy" click add.
If the qube is running, open a terminal and type "systemctl restart qubes-updates-proxy"
Whonix should be the same, ("apt-get" or "yum"), but Im not entirely sure.
Keep an eye on your logs (journalctl) and your RPC Policy.
Your RPC Policy suggests that Whonix will update through Tor,
$tag:whonix-updatevm $default allow,target=sys-whonix
so make sure sys-whonix is running.
Linux environments tend to be command line environments. You will occasionally find things that cannot be done via GUI, so its a good idea to learn how to do
things from the client.