Screen-Sharing "no network selected for sharing" problem in unity control center (18.04)

I'm using ubuntu unity desktop

unity control center > sharing > screen sharing > no network selected for sharing

connection is working fine / but don't show in sharing setting / please check screenshot

ubuntu 18.04 (but work fine in default gnome)

problem screenshot :

This seams to still be a problem even two years later. but the primary problem seams to be in Gnome-control-panel, while the background package, called vino, still works.

you can just start vino by typing: /usr/lib/vino/vino-server in a Terminal.

this will start screen sharing with all the settings set in the control panel. by ending the terminal process the screensharing also ends. Therefore if one wants to start screensharing on boot it needs to be entered into config files that execute on startup.

I am experiencing the exact same issue.

If you don't need to use networkd, I think your issue can be solved by adding this file /etc/netplan/01-network-manager-all.yaml with these contents to your netplan directory.

network:
  version: 2
  renderer: NetworkManager

After you have added this file make sure there aren't any other files in that directory that will take precedent, then use the command sudo netplan apply. You may need to do a reboot for these changes to take effect in the settings tab though.

I recently updated my netplan.yaml file to use networkd instead of NetworkManager. Since doing this my VMs are now discoverable through my network bridge but my VNC client stopped working. In the sharing page under screen sharing, I no longer have the ability to turn on screen sharing as there are no networks to be found. This of course is false as I am connected to the internet through br-mmrk1

Switching the renderer back to NetworkManager allows network sharing to be enabled again but the network itself doesn't work and I can't connect to my VNC client.

If I remove the network bridges and simply use the default NetworkManager everything works, except for my VMs of course.

Currently my work around to manage my VMs, which you may find useful if you are using your machine for Vms as well, is to manage the VMs remotely using virtual manger on another computer.

Here is the video guide for that --> https://www.youtube.com/watch?v=_SiJSz_2NaY

Here is my /etc/netplan/01-networkd.yaml file where I have to use networkd. I would be interested to see your netplan file to compare.

# This file describes the network interfaces available on your system
# For more information, see netplan(5).
network:
  version: 2
  renderer: networkd
  ethernets:
    enp2s0f0:
      mtu: 1500
    enp2s0f1:
      mtu: 1500
  bridges:
    br-mmrk1:
      addresses: [ 10.133.104.200/22 ]
      gateway4: 10.133.104.1
      nameservers:
          addresses: [ 8.8.8.8, 1.1.1.1 ]
      interfaces:
      - enp2s0f0
      mtu: 1500
      parameters:
         stp: false
         forward-delay: 15
    br-mmrk2:
      addresses: [ 10.133.56.200/22 ]
      gateway4: 10.133.56.1
      nameservers:
          addresses: [ 8.8.8.8, 1.1.1.1 ]
      interfaces:
      - enp2s0f1
      mtu: 1500
      parameters:
         stp: false
         forward-delay: 15

If you found a solution for your issue please do share here as I would be delighted with a work around for this issue as well.