Allow a guest session wifi access with no users logged in

Solution 1:

As per your comment (and mine)...

By default, connections are not shared publicly with every user on the system. In order to permit this, you need to manually enable this, which can be done either from the GUI or the terminal.

GUI Way

1. In the Network menu of a privileged account, select the Edit Connections option.
2. Select the wireless network you would like to share. Go to the General tab.

3. Select the All users may connect to this network option (see screenshot)

   

4. Click Save.

Terminal way

The network configs are saved in /etc/NetworkManager/system-connections, so we just need to edit the proper file.

1. cd to /etc/NetworkManager/system-connections and run ls. Identify the network you want to alter (usually just your SSID). In this example, I will be editing the MySSID network.

2. Run the following command to open a text editor:

   sudo nano MySSID
   

3. At the top of the file, you will see the [connections] section:

   [connection]
   id=MySSID
   uuid=<redacted>
   type=wifi
   permissions=user:kazwolfe:;
   secondaries=
   timestamp=1490727919
   

4. Find the permissions= line, and delete everything after the = sign. Your file should look like this:

   [connection]
   id=MySSID
   uuid=<redacted>
   type=wifi
   permissions=
   secondaries=
   timestamp=1490727919
   

5. Save the file with Ctrl-X.

6. Restart NetworkManager to ensure your connection settings take effect.

In your specific case (the original question), it seems like it was just a fluke that something didn't get set properly somewhere, or a setting got out of sync. Delete the network profile (from either the terminal or the GUI) and re-connect to your network. Apply the settings as above, and it should work just fine. Alternatively, you can try to dig into the config file to see what's going on, but it's likely easier to just start over.

Also, be sure you don't have multiple conflicting network profiles for a single connection. This can cause some weird issues as some are or aren't given priority over each other, making things confusing to the system.